All these 9 cases were taken up together for hearing since common question of facts and law were involved with little variation of facts in Civil Rule No.1224 of 1997, M/s SM Ispat Ltd. & another vs. State of Assam & others and Civil Rule No.2382 of 1997, M/s United Soft Drinks (P) Ltd. vs. State of Assam and Civil Rule No.2672 of 1997, Kamakhya Udyog Pvt Ltd vs. State of Assam. 2. The legality and the validity of the provisions of the Assam Industries (Sales Tax Concession) Scheme, 1995 envisaging sales tax exemption in respect of industries undertaking expansion, modernisation and diversification confined to the increase in production after expansion, modernisation and diversification are primarily challenged in these proceedings. 3. The writ petitions, inter alia, recounted the industrial policy of the State Govt. commencing from the year 1982 which provided for incentives to the new industries established within the State of Assam by way of the sales tax exemption for a period of 5 years on the sales of finished products as well as on the purchase of raw materials. The State Govt., thereafter, introduced a new industrial policy whereby incentives were offered to the new industries established in the State as well as to the existing industries undertaking expansion, modernisation and diversi­fication. The Assam Industries (Sales Tax Concession) Act, 1986 was enacted in the year 1987 amending certain provisions of the existing sales tax law and granting sales tax exemption to the new industries. According to the petitioners, the above Act was made applicable to the new industries established within 15.10.1982 to 31.3.1990 and therefore the said Act does not have bearing whatsoever to the industries set up after said period. In the year 1991 the Govt. of Assam announced a new industrial policy whereby incentives were offered by way of sales tax exemption for a period of 7 years to the new industries as well as the industries undertaking expansion, modernisation and diversification. The exemption was granted on the sale of finished products as well as on the purchase of raw materials. 4. The State Govt., thereafter, came with the Assam Industries (Sales Tax Concession) Scheme, 1995 dated 16.8.1995 which came into force on 1.4.1991. The exemption was granted on the sale of finished products as well as on the purchase of raw materials. 4. The State Govt., thereafter, came with the Assam Industries (Sales Tax Concession) Scheme, 1995 dated 16.8.1995 which came into force on 1.4.1991. The impugned scheme, according to the petitioners prejudicially affected the vested rights of the assesses conferred by the earlier scheme and the same is also contrary to the provisions of the Assam General Sales Tax Act, 1993. In deciding these cases for the purpose of convenience, I shall hereinafter refer to the facts pleaded in Civil Rule No.3673 of 1996, Manjushree Extrusions Ltd & another vs. State of Assam & others. 5. Like the other petitioners, the petitioner in this civil rule is also an existing registered small scale industry. The production of the company commenced on and from 1.6.1989. Prior to the establishment of the company the Govt. of Assam announced a new package of incentives under the 1986 Industrial Policy vide notification dated 25.12.1986. On the application of the petitioner company the competent authority, namely, Udyog Sahayak, Director of Industries, issued an Eligibility Certificate on 27.8.1990 and the Superintendent of Taxes in pursuance of the provisions of section 2 of the Assam Industries (Sale Tax Concessions) Act, 1986 granted exemption amongst others from payment of sales tax with effect from 1.6.1989 to 31.5.1994 vide Annexure II. The petitioner company was also granted certification of authorisation by the Superintendent of Taxes in terms of the provisions of section 4 (2) of the Assam Industries (Sales Tax Concession) Act, 1986 (the Act of 1987), certifying that no tax liability under Assam Sales Tax Act, 1947 or as the case may be, the Assam Sales of Petroleum and Petroleum Products including Motor Spirit and Lubricants Taxation Act, 1955 or the Assam Finance (Sales Tax) Act, 1956 in respect of its sales to the holder of the goods specified in Table 'B' of the certificate for use by the holder as raw materials in the manufacture of goods specified in Table 'A' of the certificate in the industrial unit (s) mentioned therein for the sale by the holder subject to production of declaration as specified in sub-section (2) of section 3 of the 1986 Act. The Govt. The Govt. of Assam, in the meantime announced the 1991 Industrial Policy vide notification dated 1.7.1992 conferred amongst others the benefit of sales tax exemption to the industrial units specified in the said policy. The incentive under the policy was to remain in operation for a period of 5 years commencing from 1st April, 1991 or till such time as was to be thought proper by the Govt. Above policy provided with for the benefit of sales taxes exemption on purchase of raw materials and on sale of finished products for a period of 7 years. The company undertook expansion work in its industrial unit and made additional investment in the industrial unit. The annual capacity of the industrial unit in respect of the petitioner/company was increased to 42 MT and in respect of the polythene bags, tube pouch, sheet etc. of HOPE LLDPE and LDPR, by 32 MT; and the General Manager, DIG Kamrup, accordingly issued and annual assessment certificate on 1.6.1994. Similarly, the eligibility certificate under the Industrial Policy of 1991 dated 28.4.1994 was issued to the petitioner which reflected, amongst others, sales tax exemption from 1.5.94 to 30.4.2001 (Annexure VI to the writ petition). 6. All the petitioners based their claims for sales tax exemption amongst others on such eligibility certificate issued by the competent authority in all the cases. 7. According the petitioners on the strength of the eligibility certificate issued by the appropriate authority read with the 1991 Scheme, the petitioners were entitled for the exemption from payment of sales tax on raw materials and on finished products for 7 years. Acting on the Govt. Policy of 1991 and the eligibility certificate, the petitioners sold their products without charging any sales tax and purchased raw materials for use in manufacture of finished products without payment of taxes. According to the petitioners, the Govt. Industrial Policy, as mentioned above, conferred a right on the petitioners to get the benefit of exemption of tax and on the strength of the above policy, the petitioners relying upon the said representation unequivocally pronounced by the respondents fully acted upon it, the State Government instead of acting upon the said promise shifted its position in a most illegal fashion by introducing Assam Industries (Sales Tax Concession) Scheme, 1995 (hereinafter referred to 1995 Scheme). 8. 8. The petitioner questioned the legality of the procedure relating to determination of increase in production for the purpose of granting sales tax relief to the industries undertaking expansion, modernisation and diversification when beyond the powers conferred on the State Govt. by section 9 (4) of the Assam General Sales Tax Act, 1993 read with sub-section (3) (f) of section 74 of the Act. It was further contended that the aforesaid provision of concession scheme provide for determination of increase in production were violative of Article 14 of the Constitution of India on the ground that it brought distinction between industry which was running very good prior to expansion but could not do better production after expansion due to numerous difficulties due to the non-availability of power, raw materials and other like imponderables. 9. The petitioner also contended that on the unequivocal promise of the respondents, petitioners made sales of their products without charging any tax. Petitioner company also purchased raw materials to be used on the industrial unit without payment of any sales tax on the strength of the above promise/assurance and or representation given by the State Govt.. The petitioners altered their position and made huge investment in business by undertaking expansion, modernisation and diversification. The petitioners contended that the representations coupled with the conduct of the Govt. culminated into a promise of the Govt. assuring the company that it would not be liable to pay of sales tax on purchase of raw-materials and finished products for a period of 7 years, on the strength of which the petitioners has acted upon all through out and the respondents therefore are estopped in law to resile from its promise and to adopt any course contrary to their representation. The petitioners accordingly sought for writ of Mandamus commanding the respondents to carry out the assurance and promise made to them to the effect that the petitioners industrial units would be entitled to sales tax exemption for a period of 7 years. 10. The respondents denied and disputed the assertions made in the writ petitions. The respondents admitted that the petitioner is a dealer under the relevant taxation statute. The respondents referred to Sales Tax Concessions Act, 1986. 10. The respondents denied and disputed the assertions made in the writ petitions. The respondents admitted that the petitioner is a dealer under the relevant taxation statute. The respondents referred to Sales Tax Concessions Act, 1986. The said Act was extended and made applicable to the new industrial units registered as industrial units in which cases effective steps were completed or taken after 15th October, 1982 but before 31st March, 1990. The respondent denied that incentive under the Assam Industrial Policy 1991 so far as sales tax was concerned for a period of 7 years. The respondents pointed out in its affidavit in the case of Civil Rule No.3673 of 1996 that the petitioners were not eligible for sales tax exemption from 1.4.1994 to 30.4.2001. The certificate as stated in Annexure VI showing sales tax exemption upto 2001 was contrary to the law. According to the respondents, the petitioners can take advantage of the certificate upto 30.4.2001 only for the extended portion only and cannot derive the benefit thereof for the entire period. The respondent denied and disputed the claim of the petitioners to get exemption from payment of sales tax on purchase of raw-materials and on finished products for a period of 7 years as alleged. The respondents further disputed that the respondent gave any undertaking to the petitioners' company for not realising the sales tax from them. According to the respondents an unit would be entitled sales tax exemption only for extended portion of the unit and not for the entire unit. The original units of the petitioners had already enjoyed the sales tax exemption for five years. After coming into force of the Assam General Sales Tax, 1993, area relating to the matter of the tax exemption is taken care of by the above Act and the scheme framed thereunder and, therefore the matters are now covered by the Act which would only regularise the field of exemption. The statutory scheme made under section 9 (4) of the 1993 Act would hold the field governing exemption regarding sales tax superseding the earlier decisions, if there be any. 11. At this stage, it would be convenient to refer to some of the provisions of the Industrial Policy of 1991. The statutory scheme made under section 9 (4) of the 1993 Act would hold the field governing exemption regarding sales tax superseding the earlier decisions, if there be any. 11. At this stage, it would be convenient to refer to some of the provisions of the Industrial Policy of 1991. "1.1: The new package of incentives herein after referred to as 1991 Incentive Scheme shall remain in operation for a period of 5 (five) years commencing from 1.4.91 or till such time as the Government may consider fit and proper. The Government also reserve the right to make any amendments to the scheme. However, in such case proper notice will be given and also the commitments already made will not affected by such amendments. 2. Eligible unit: Only new units set up on or after 1.4.91 and existing units, undertaking expansion modernization or diversification at the same location or at any where place in the State of Assam will be eligible for incentives under 1991 Scheme provided that. 4. Existing unit: A unit which is or was in commercial production at any time prior to 1.4.91 will be considered as an existing unit for the purpose of the 1991 Scheme. 5. Expansion/Modernization/Diversification : Expansion/modernization/ diversification of an existing industrial unit will also be eligible for all incentives if the total capital investment on plant and machinery in the expansion/ modernization or diversification as the case may be, is more than 25 percent of the total fixed capital investment of the existing unit. For the purpose of calculation, gross value of all the capital investments made on land, building, plant & machinery of an existing unit will be taken into consideration. Expansion, modernization, diversification will imply an increase of at least 25% in the existing installed capacity as well as increase of additional employment at least by 10%. The fact existing unit has availed itself of incentives will not disqualify the expansion/modernization/diversification project to get incentives for the extra investment made. 8. No right of claim for any incentive under the scheme shall be deemed to have been conferred by the scheme merely by virtue of the fact that the unit has fulfilled on its part the conditions of the scheme. 8. No right of claim for any incentive under the scheme shall be deemed to have been conferred by the scheme merely by virtue of the fact that the unit has fulfilled on its part the conditions of the scheme. The incentives under the Scheme cannot be claimed unless the Eligibility Certificate has been issued under the scheme by the implementing agency concerned and the unit has complied with the stipulations/conditions of eligibility. 6. Sales tax exemption : Sales Tax will be exempted on purchase of raw materials and sales of finished products for a period of seven years. 12. The 1995 Scheme was framed by the State in exercise of its statutory power conferred under sub-section (4) of section 9 read with clause (f) of sub­section (3) of section 74 of the Assam General Sales Tax Act, 1993 with a view to grant relief by way of full exemption of sales tax on purchase of raw materials within the State by the eligible industrial units, situated within the State as also on the sale of finished products, manufacture in such eligible units in the State or in the course inter State trade or commerce. The scheme was declared to be deemed to be force with effect from 1.4.91. The relevant features of the said scheme are extracted below: "'A' A new industrial unit having its registered office within the State of Assam, which has completed the final effective steps shall be an eligible industrial unit for the purpose of this scheme. An industrial unit, which has completed all the initial effective steps on or after 1.4.91 shall be considered as a new unit. A new unit shall be deemed to have completed all initial effective steps, if all the following have been achieved : Effective possession of land of the site of the unit. Registration of the firm or the company or the society or the trust with the appropriate authority. Provisional Small Industries Registration/Secretariat Industrial Approval Registration or any other statutory registration with the appropriate authority. Project report in respect of the industrial unit has been prepared. Power for the industrial unit has been sanctioned. Means of finance for the industrial unit is completed including sanction of term loan. A industrial unit shall be deemed to have completed the final effective steps, if all the following have been achieved : Disbursement of term loan to the full extent. Power for the industrial unit has been sanctioned. Means of finance for the industrial unit is completed including sanction of term loan. A industrial unit shall be deemed to have completed the final effective steps, if all the following have been achieved : Disbursement of term loan to the full extent. Completion of the installation of the plant & machinery. Receipt of all relevant approvals and clearances from the appropriate authorities viz pollution control clearance, capital goods clearance, explosive substance clearance, Municipal clearance etc. Connection of power service. Allotment of raw materials, whether applicable. Sanction of working capital. Commissioning of the plant. Compliance with the criteria on the industrial units employing the people of Assam. 'B' An industrial unit, having its registered office within the State of Assam which is or was in production at any time prior to 1.4.91 undertaking expansion/ modernisation/diversification to the minimum extent of 25% at the same location or at other place (s) of the State of Assam and with an additional employment atleast by 10% and is an compliance with the criteria on the industrial unit's employing the people of Assam shall be treated as an eligible industrial unit for the purpose of this scheme. For the purpose of getting benefit under this scheme, the minimum extent of expansion/modernisation/diversification as referred to above shall be 25% of the total fixed capital investment of the unit prior to such expansion/modernisation/ diversification. For the purpose of calculation of gross value, all capital investment made on land, building, plant and machinery of a unit which is or was in production at any time prior to 1.4.91 shall be taken into consideration. 7. Determination of increase in. production of an industrial unit which undertakes expansion/modernisation/diversification : The actual production of the industrial unit during 365 consecutive working days of the unit, preceding the date of completion of its expansion/modernisation/ diversification shall be called its base year production. The actual production of the industrial unit after its expansion/modernisation/ diversification shall be determined on an yearly basis, the first year being the 365 working days following the date of commencement of production after tile completion of the expansion/modernisation/diversification. Increase in production of an industrial unit after the completion of expansion/ modernisation/diversification -shall be equal to the annual production after the completion of expansion/modernisation/diversification minus production during the base year divided by the base year production, expressed in percentage. 11. Increase in production of an industrial unit after the completion of expansion/ modernisation/diversification -shall be equal to the annual production after the completion of expansion/modernisation/diversification minus production during the base year divided by the base year production, expressed in percentage. 11. Procedure for the extension of benefit under the scheme to an eligible industrial unit under the category 'B' which obtains the certificate of authorization on or after the date of issue of this notification, dated the 16th August, 1995 but whose certificate of authorisation is in force prior to the date of issue of this notification dated the 16th August, 1995, but from or after 1,4.91 : (a) (1) Corresponding to the extent of requirements of the permitted raw materials (stated in the certificate of authorisation, granted to the aforesaid industrial unit) in reference to the difference between the actual annual production after the completion of the expansion/modernisation/diversification and the annual production during the base year, the benefit of sales tax, as entitled under the scheme shall be allowed by way of refund to such eligible industrial unit on application, filed before the Assessing Officer of the area within 180 days from the date of issue of the certificate of authorisation. The refund shall be governed by the provision of section 30 of the Assam General Sales Tax Act, 1993 and Rules made thereunder. (ii) During the period from or after the date of issue of this notification dated the 16th August 1995, the benefit of sales tax relief as entitled under this scheme in the purchase of permitted raw materials stated in the certificate of authorisation granted to any of the above mentioned eligible industrial units of Category 'B' under this para 11 shall be available to it in the same manner as laid down in sub para (a) of para 10 : Provided that until the determination of base year production of the annual production after the expansion/modernisation/diversification or both, the benefit under this scheme in respect of the raw materials shall not be admissible to an eligibly industrial unit of the category 'B'. After these are determined the benefit to the extent as entitled under this scheme in respect of the raw materials shall be allowed to the aforesaid eligible industrial unit under the category 'B' by way of refund on application filed by it before the Assessing Officer of the area within 90 days from the date of determination of these data. The refund shall be governed by the provision of section 30 of the Assam General Sales Tax Act, 1993 and Rules made thereunder. (b) With regard to the sale of the finished products, the following shall be procedure: Corresponding to the difference between the actual annual production after the completion of expansion/modernisation/diversification and the annual production during the base year, the holder of the certificate of authorisation in the case of an eligible unit of the category 'B' under this para 11 shall be competent to sell his finished products in the State of Assam or in the course of inter State trade or commerce, for which he shall not be liable to pay sales tax under the Assam General Sales Tax Act, 1993. In the cash memorandum or the bill, issued to the purchaser, the holder of the certificate of authorisation shall clearly mention the reference particulars of his certificate of authorisation and such copy of the cash memorandum or bill shall be verified by the Assessing Officer of the area at the time of assessment of his sales tax dues : Provided that a holder of the certificate of authorisation as aforesaid shall not collect sales tax on his sales from that portion of the finished products, which is declared eligible for sales tax exemption in the certificate of authorisation. In case he collect sales tax on such sales, the amount of sales tax so collected shall be deposited by him into the Govt. treasury : Provided further that until the determination of base year production or the annual production after the expansion/modernisation/diversification or both, the benefit under this scheme in respect of finished products shall not be admissible to an eligible industrial unit of category 'B'. 13. Mr. PK Goswami, learned senior counsel assisted by Shri Ranjan Gogol and Dr. AK Saraf Advocates drawn my attention to the relevant schemes as well as the statutory provisions. Mr. 13. Mr. PK Goswami, learned senior counsel assisted by Shri Ranjan Gogol and Dr. AK Saraf Advocates drawn my attention to the relevant schemes as well as the statutory provisions. Mr. Goswami, learned senior counsel submitted that the Industrial Policy of 1991 contained an unequivocal promise of full sales tax exemption for a period of seven years to new industries as well as industries undertaking expansion, modernisation and diversification. The petitioners have acted on the said promise held out by the State Govt. and accordingly changed their position. The 1995 Scheme only sought to provide partial exemption to the industries undertaking expansion etc. i.e. exemption in respect of expanded portion only is contrary to its promise and therefore impugned actions of the respondents are liable to be struck down. Mr. Goswami, in support of his contention relied on the doctrine of promissory estoppel which is founded as public policy and public interest. Mr. Goswami learned senior counsel pointed out that the State Govt. generated a genuine expectation on the petitioner by its promise on the basis of which the petitioners changed its position and without any valid reasons the respondent cannot resile from the same. The learned senior counsel pointed out the actions of the authorities in issuing the eligibility certificate under the 1991 Policy to each of the petitioners certifying the petitioners to be eligible for full sales tax exemption for a period of 7 years as well as the acceptance of returns submitted by the petitioners showing NIL sales tax liability, all these factors read with the scheme create an estoppel against the State Govt. from adopting course of action contrary to the promises made. In 1995 Scheme seeking to grant partial exemptions to industries undertaking expansion etc. i.e. exemption in respect of expanded portion only is equally unlawful submitted Mr. Goswami. 14. Mr. Goswami, learned senior counsel for the petitioners, thereafter, submitted that no notification providing relief by way of full or partial exemption under section 9 (4) read with section 73 (3) (f) of the Assam General Sales Tax Act, 1993 can be made with retrospective effect to take away the accrued or vested rights of the petitioners. Section 9 (4) is prospective in operation submitted the learned senior counsel. Section 9 (4) is prospective in operation submitted the learned senior counsel. Section 74 (3) (f) of the Act protects and preserves exemption already granted prior to the appointed date as if the same were under the 1993 Act. Emphasising on the aforesaid provision of the Act, learned senior counsel submitted that the statutory provisions did not confer upon the authority with the power to issue notification with retrospective effect to take away accrued rights. Mr. Goswami, further submitted that the petitioners having undertaken the work of expansion/modernisation and diversification in response to the unequivocal promise held out in 1991 Policy and such works having been completed within the laid down parameters and petitioners having been certified to be eligible for full exemption, the vested rights accrued upon the petitioners cannot be taken away retrospectively. It was submitted that the notification dated 16.8.1995 introducing in 1995 Scheme is an executive-cum-statutory act that the State Govt. in exercise of the executive powers and statutory function is not entitled to take away the vested or accrued rights. Learned senior counsel Mr. Goswami, after referring section 7 of the Assam Sales Tax Act, 1947 pointed out that the State Govt. conferred full exemption from the sales tax in 1991 Policy and in the light of the above provision to exempt any goods from the payment of sales tax. Alternatively it was submitted that the industrial policy notification is in exercise of powers under Article 162 of the Constitution and the rights already accrued under such a notification cannot be taken away by a subsequent notification issued by the State Govt. in exercise of its executive powers. Learned senior counsel submitted that the impugned provisions of the scheme of 1995 are arbitrary and volatile of Article 14 and 19 (1) (g) of the Constitution of India inasmuch as the sales tax benefit under the scheme have been linked up with the production of an industrial unit which cannot be said to be a reasonable criteria for the grant of sales tax exemption. Further, it is not necessary that by undertaking expansion, modernisation and diversification work the production must increase. Increase in production cannot be logical corollary to the expansion, modernisation and/or diversification of the industry. Further the Industrial Policy of 1991 only stipulated increase of capacity by 25% which can never mean increase in production. Further, it is not necessary that by undertaking expansion, modernisation and diversification work the production must increase. Increase in production cannot be logical corollary to the expansion, modernisation and/or diversification of the industry. Further the Industrial Policy of 1991 only stipulated increase of capacity by 25% which can never mean increase in production. Mr Goswami, further criticised the provision for determination of increase in production taking the period of 365 days prior to expansion as the base year and the production after 365 days of expansion to be the actual production and to grant tht benefit on the difference of actual production and base year production as arbitrary and impracticable so much so the production in the 365 days after expansion may not increase due to various factors like non-availability of raw materials, electricity problem, market situation etc. and other like numerous causes. If the provisions of the scheme are applied, argued the learned senior counsel then in case of an industry whose production has not increased in the first 365 days after expansion will not be entitled to any benefit of sales tax exemption at all during the remaining period of six years, notwithstanding the fact that subsequently such production may go up substantially. Mr. Goswami, lastly submitted that the provisions of the impugned scheme seeks to fasten unforeseen and severe financial liabilities on the petitioners who have become liable to pay sales tax in respect of part of production for a period prior to the framing of the scheme though no tax has been collected by the petitioners on the basis of the promise made. A scheme contrary to the promise of full exemption and additionally imposing a heavy financial burden in respect of periods prior to framing of the scheme is per se arbitrary and unreasonable and violative of the fundamental rights of the petitioners regulated under Article 14 and 19 (1) (g) of the Constitution of India, submitted learned senior counsel Sri Goswami. 15. Mr. Goswami also argued that in a given case, for compelling reasons it may be permissible for the State to avoid its promise, pleading compelling necessity in the ground of public policy and interest. In the absence of such situation the respondents cannot be permitted to resile from its promise. In support of his contention Mr. 15. Mr. Goswami also argued that in a given case, for compelling reasons it may be permissible for the State to avoid its promise, pleading compelling necessity in the ground of public policy and interest. In the absence of such situation the respondents cannot be permitted to resile from its promise. In support of his contention Mr. Goswami, learned senior counsel, referred to (1992) 2 SCC 411 , Amrit Banaspati vs. State of Assam. Learned counsel further also referred in details to the decisions in Motilal Padampat Sugar Mills Co. Ltd. vs. State of Uttar Pradesh & others on the issue of Promissory Estoppel, reported in 44 STC 42. In addition the learned the learned senior counsel also referred the following decisions, Pouraami Oil Mills vs. State of Kerala & another reported in 65 STC 1; Assistant Commissioner of Commercial Taxes (ASST) Dharwar & others vs. Dharmendra Trading Company, reported in 70 STC 59; Shri Guru Ashish Wire Industries vs. State of Gujarat reported in 92 STC 286. 16. The learned senior counsel for the petitioners in course of his argument cited numerous decisions including MP Sugar Mills Co, vs. State of UP, (1979) .2 SCC 409; Union of India vs. Godfray Phillips India, (1985) 4 SCC 369 ; Pournami Oil Mills vs. State of Kerala, 106 STC 138; Shri Bakul Oil Industries vs. State of Gujrat, (1987) 1 SCC 31 etc. 17. Mr. HN Sarma, the learned Addl.. Senior Govt. Advocate appearing on behalf of the respondents excepting the Civil Rule No.2672 of 1997 M/s Kamakhya Udyog Pvt. Ltd & another vs. State of Assam in which case Mr. KH Choudhury, learned Addl.. Senior Govt. Advocate, Assam appeared for the respondents. According to Sri Sarma, the learned counsel for the respondents, the policy of sales tax exemption was formulated on the strength of the industrial policy of 1982-86. The above benefit was statutorily recognised in the Tax Concession Act, 1986 amending Sales Tax Act, 1947 and by inserting a new section therein. As per the Concessions Act, tax concessions were provided to the new industrial unit was available for a period of 5 years from the date of commencement of the production. Industries of all the petitioners having been set up within the period between 15.10.82 to 31.3.90, these units cannot take advantage of exemption in payment of sales tax beyond the period of 5 years. Industries of all the petitioners having been set up within the period between 15.10.82 to 31.3.90, these units cannot take advantage of exemption in payment of sales tax beyond the period of 5 years. The exemption as per the industrial policy were already enjoyed by the petitioners. The petitioners now wanted to get extra advantage by taking resort to expansion/modernisation/ diversification on the alleged strength of extra investment for their original unit for further period along with the expanded portion such exemption is not permissible under the Concession Act, 1986 or section 3A of 1947 Act, submitted Mr. HN Sarma, learned Govt. Advocate. Learned Govt. Advocate pointed out that the 1991 Industrial Unit Policy was only a guideline and not a statutory one. Mr. Sarma pointed out that the petitioners failed to establish a case of any promissory estoppel where by the petitioners changed its position to their prejudice on the strength of their promises. Learned Govt. Advocate invited my attention to the 1991 Scheme and submitted that 1991 Policy contains no promise. A new industrial policy was formulated on reviewing the 1986 Policy. The learned Govt. Advocate pointed out that 1991 Scheme being a policy of the Govt. for attainment of certain objective, it is always open for the Govt. to change the said policy from time to .time to meet the situation. Learned Govt. Advocate further argued that 1995 Scheme being statutory scheme framed under the Tax Act 1993 it is a statutory in character and therefore there cannot be any estoppel against the statute or statutory provision. Learned Govt. Advocate Shri Sarma pointed out that the Govt. having reserved its power within itself to review the industrial policy from time to time, it was within itself competent to withdraw the scheme. The Tax Act was enacted on repealing the Tax Act, 1947, Assam Sales of Petroleum and Petroleim Products etc Taxation Act, 1955, Assam Purchase Act, 1957, the Sales Tax Act 1993 came into force on 1.7,1993. Mr. Sarma the learned Addl.. Senior Govt. Advocate pointed out that the Act in question was not under challenge and provision of the Scheme of 1995 was made on the strength of the 1993 Act and, therefore, the statutory scheme will prevail over any promise arising there be held to be a promise. Mr. Mr. Sarma the learned Addl.. Senior Govt. Advocate pointed out that the Act in question was not under challenge and provision of the Scheme of 1995 was made on the strength of the 1993 Act and, therefore, the statutory scheme will prevail over any promise arising there be held to be a promise. Mr. Sarma also emphatically ruled out the contention of unworkability of the provisions contained in clauses 4,5,7,10 and 11 of the scheme. 18. In support of his contention Mr. Sarma, the learned Addl.. Senior Govt. Advocate referred to following decisions: Kasinka Trading & another vs. Union of India & another reported in AIR 1995 SC 874 : (1995) 2 SCC 274; Union Territory of Chandigarh vs. Managing Society, Goswami GDSDC reported in (1996) 7 SCC 665 and Shirjee Sales Corporation vs. Union of India reported in (1997) 3 SCC 398 . 19. In Civil Rule No. 1224 of 1997, SM Ispat Ltd. vs. State of Assam : the writ petition is directed against the withdrawal of the benefit of this scheme in the matter of manufacture of galvanised corrugated sheets units. The petitioner in the above civil rule is a company which was at all relevant time was engaged in galvanised sheets and corrugated sheets. Pursuance to the earlier scheme the petitioners were provided with the benefit. The same was taken away from the scheme without any valid reason. 20. Mr. R. Gogoi, learned counsel appearing on behalf of the petitioner also adopted the same plea that was taken by Mr. Goswami. 21. Mr HN Sarma, learned Addl.. Senior Govt. Advocate, on the other hand pointed out that the authority in its wisdom excluded the 13 other industries from the scheme informity with the statutory provisions and therefore same cannot be faulted at Mr. Sarma pointed out that in the above case eligibility certificate was granted in the name of SM Ispat Ltd. and therefore the petition, according to the learned Govt. Advocate is liable to be dismissed. 22. In the case of United Soft Drinks Pvt Ltd vs. State of Assam, in Civil Rule No.2382 of 1997, the petitioner company engaged in manufacturing a soft drinks and was granted an eligibility certificate dated 12.7.1993 under the 1991 Industrial Policy certifying that the petitioner was entitled to sales tax exemption for the period with effect from 10.5.1993 to 9.5.2000. In the case of United Soft Drinks Pvt Ltd vs. State of Assam, in Civil Rule No.2382 of 1997, the petitioner company engaged in manufacturing a soft drinks and was granted an eligibility certificate dated 12.7.1993 under the 1991 Industrial Policy certifying that the petitioner was entitled to sales tax exemption for the period with effect from 10.5.1993 to 9.5.2000. The exemption was limited and on the strength of the eligibility certificate an authorisation certificate was issued on 31.7.1993, similarly limiting its exemption. The assessment for the period 30.6.93 to 31.3.94 was completed treating the sales tax liability as nil. By letter dated 17.4.95 the Superintendent of Taxes issued show cause notices to the petitioner company proposing cancellation of the authorisation certificate dated 31.7.93. The petitioner showed cause on 24.5.95. Thereafter by notice dated 1.6.95, the Superintendent of Taxes proposed reopening of the completed assessments made for the period aforementioned on the ground that the petitioner is entitled to exemption upto 25%. Thereafter a fresh eligibility certificate dated 5.8.95, deleting the 25% exemption as mentioned in the earlier eligibility certificate was issued on the basis thereof a fresh authorisation certificate dated 29.8.95 was issued covering the period of exemption from 10.5.93 to 9.5.2000. On 11.3.97, the Superintendent of Taxes issued a notice advising it to submit a fresh eligibility certificate in Form IIB failing which the earlier eligibility certificate dated 5.8.95 was threatened with cancellation -The petitioner was also asked to surrender the authorisation certificate dated 29.8.95. By notice dated 9.4.97, the petitioner company was asked to show cause as to why sales taxes should not be levied with effect from 10,5.93 and why the earlier assessments are not to be rectified. It is in these circumstances the petitioner moved this Court for cancellation of the various notices and orders as alleged and arbitrary in addition to the other grounds raised in the case of Manjushree Extrusions vs. State of Assam & others. 23. Mr. HN Sarma, learned Addl.. Senior Govt. Advocate, on the other hand submitted that the petitioners were wrongly granted full concession for the entire unit on the basis of the irregular authorisation certificate. Since the above certificate was wrongly issued, notice for necessary correction was issued to the petiitioner to show cause for re-assessment and irregularities were detected later on regarding the period ending 31.3.1996 and the petitioner prayed time for reply to the notice. Since the above certificate was wrongly issued, notice for necessary correction was issued to the petiitioner to show cause for re-assessment and irregularities were detected later on regarding the period ending 31.3.1996 and the petitioner prayed time for reply to the notice. The eligibility certificate was issued only for the expanded period portion and not for whole unit. The oil unit of the petitioner was already granted an exemption of tax amounting to Rs 58,56,102 on sales turnover amounting to Rs. 37,36,01,279.00 for the period from 29.4.88 to 31.3.98. The learned counsel for the respondents submitted that the petitioner cannot take advantage on the aforesaid eligibility certificate which was wrongly granted. The petitioner cannot take advantage more than his legal dues. Taxing authority has already taken steps under the law and therefore law should be allowed to take its own course, submitted the learned Addl. Senior Govt. Advocate. 24. The petitioner company in Civil Rule No.2672 of 1997, Kamakhya Udyog Pvt. Ltd & another vs. State of Assam were engaged in manufacturing rigid PVC pipes. The unit was set up in 1982.The petitioner claimed that on the basis of the announcements made in the .Industrial Policy of 1991, the petitioner company established a new unit in the same premises for manufacture of plastic water storage tanks. The petitioner invested a total of Rs.73.84 lakhs in the said new unit. The establishment started work in the new unit started on 31.3.1992 and was completed on 12.4.93. The Director of Industries by a registration certification dated 7.5.93 certified that the date of commencement of commercial production as 12.4.93. Thereafter, eligibility certificate dated 11.6.93 was issued certifying the unit of petitioner company to sales tax exemption from 12.4.93 to 11.4.2000 and treating the water storage unit as a diversification work of the existing unit. 25. After coming into force of the 199.5 Scheme, the petitioner submitted an application dated 3.11.95. for eligibility certificate. The petitioner claimed eligibility as a new unit and submitted an application in Form 1 A. However, an application in Form IB was also submitted since the same was requested by the authority. Thereafter, eligibility certificate was issued on 24.6.96 in Form IIB as a unit undertaking expansion, modernisation and diversification. On 4.7.96, the Director of Industries issued registration certificate in respect of the water storage tank treating it as Unit II of the petitioner company. Thereafter, eligibility certificate was issued on 24.6.96 in Form IIB as a unit undertaking expansion, modernisation and diversification. On 4.7.96, the Director of Industries issued registration certificate in respect of the water storage tank treating it as Unit II of the petitioner company. The petitioner submitted an application before the sales tax authority for the grant of authorisation certificate on 26.6.96. In response to the said application the Superintendent of Sales Tax issued a letter dated 18.7.96 stating that the petitioner's water storage unit is a new unit and therefore is eligible for sales tax under the category A and not under category B. Superintendent of Sales Tax informed the petitioner that till the eligibility of the petitioner as a new unit is decided, the matter of issuance of authorisation certificate shall be kept in abeyance. Subsequently, the petitioner company wrote to the authorities of the State for the grant of an eligibility certificate treating the water storage unit as a new unit which has been refused by communication dated 31.5.97. Hence, this writ petition. In the letter of Superintendent of Taxes dated 18.7.96 it was stated that the water storage unit of the petitioner was treated as a new unit. The petitioner contends that the decision contained in the communication dated 31.5.1997 is liable to be quashed since the petitioner took all requisite steps in respect of water storage unit for being treated as new unit on the strength of the decision reported in 104 STC 470. 26. The respondents on the other hand contended that under the Industrial Policy, 1991 all incentives including sales tax exemption were made for new units started on or after 1.4.91 and not before 1.4.91 as has mentioned. The unit of the petitioner was registered with the Industries Department (District Industries Centre, Kamrup, Guwahati) Govt. of Assam under Registration No.02/05/02240/ PMT/SST dated 20,8.83 and the date of commencement of production was 05.12.82. Initially the item of production was Rigid PVC pipes. Subsequently, on the application of the unit on 5.2.93, the production of plastic water tank for water and other allied products were included as additional item of production in the registration certificate for the same unit having the same power connection, there was no case for issuing a separate registration as a new unit as it was neither a new unit nor the unit applied for a new registration during that time. The petitioner in its own enthusiasm also mentioned wrongly that Director of Industries included the new item in this registration certificate despite its full knowledge that it was General Manager, District Industries Centre, Kamrup and not Director of Industries, who issued the registration certificate. 27. The respondents stated the petitioner unit is an existing unit which has undergone expansion/diversification and is certainly not a new unit as asserted by the petitioner. The claim for treating its water tank unit was not accepted by the Director of Industries, so much so unit firstly did not apply at all in proper form to the Director of Industries to consider the water tank unit to be a new unit. Secondly in their application dated 3.11.95 to the General Manager, District Kamrup, the petitioner had submitted simultaneously both the Form IA and IB which are meant for new unit and existing units undergoing expansion/ diversification respectively. If the petitioner unit was genuinely a new unit and were sure of their status, they would have submitted their application only in Form IA meant for new unit instead of submitting both Form IA and IB which clearly shows that the petitioner unit was only trying to take a chance. The District Industries Centre, Kamrup, not the Director of Industries as mentioned in application had registered the extended part (meant for diversification) on 24.7.96 as new unit. Subsequently, on enquiry, it is found that there is no merit in treating the extended/diversified part as a separate and independent unit as the unit was maintaining a common cash book for both the part and there was only one electric metre allowed by the ASEB of both the parts. Bank loan was sanctioned on 30.6.93 to the original unit i.e. to M/s Kamakhya Udyog (P) Ltd. to implement the diversification project for manufacture of Rotomoulded Water Tank not to the M/s Kamakhya Udyog (P) Ltd Unit II. The necessary steps to modify the registration certificate issued on 4.7.96 have been initiated. It was further submitted that the construction of a new factory building arrangement of term loan and procurement and installation of a new machinery are not sufficient aspects for categorisation of new unit. For diversification of an existing unit all the above steps are necessary. The necessary steps to modify the registration certificate issued on 4.7.96 have been initiated. It was further submitted that the construction of a new factory building arrangement of term loan and procurement and installation of a new machinery are not sufficient aspects for categorisation of new unit. For diversification of an existing unit all the above steps are necessary. The fact that same cash book and same power connection was being shared by original as well as diversified unit negates the categorisation of water tank unit as a new unit. Moreover for a new unit, the first step should be the registration with the District Industries Centre as a SSI unit after which only all facilities, namely, sanction of loan from bank and financial institutions, power sanction etc follow. 28. The matter was discussed in detail in the 3rd State Level Committee held on 15.3.97 and the committee, after examining the papers, did not consider the petitioner's plea of treating the water tank part as a new unit as valid. The relevant extract of the proceedings of the said meeting reads as follows : "Matter relating to issuance of eligibility certificate to M/s Kamakhya Udyog Pvt. Ltd. Birkuchi, Narengi. The proposal of the eligibility certificate of the said unit was placed before the 1st SLC held on 19.2.96. The committee had approved the proposal as an unit undergoing expansion. All documents submitted by the industrial unit and the GM DIG, Kamrup revealed that the unit had made substantial expansion and was eligible for availing the sales tax incentive under the scheme. But, after issuance of eligibility certificate on sales tax, the unit had approached the Commissioner of Industries with an appeal stating that they have got a separate registration certificate for the new products and earlier proposal is to be cancelled and a fresh eligibility certificate should be issued in favour of their unit as they have produced new items with new machinery. The matter was further enquired through Addl.. Director of Industries (FP) and the enquiry reports was placed before the committee for necessary action. The Committee after detailed discussion opined as below : The Committee considered the letter of M/s Kamakhya Udyog Pvt. Ltd vide their letter dated 23.7.96 requesting for treating his unit M/s Kamakhys Udyog Pvt. Ltd as a new unit instead of diversified old unit. Director of Industries (FP) and the enquiry reports was placed before the committee for necessary action. The Committee after detailed discussion opined as below : The Committee considered the letter of M/s Kamakhya Udyog Pvt. Ltd vide their letter dated 23.7.96 requesting for treating his unit M/s Kamakhys Udyog Pvt. Ltd as a new unit instead of diversified old unit. The unit was issued eligibility certificate in Form HB on the basis of recommendation of SLC held on 19.2.96 treating the unit as diversified unit. In their petition dated 23.7.96 M/s Kamakhya Udyog Pvt. Ltd has contended that the concerned authority wrongly granted above mentioned certificate. The Committee has gone through the records and it is very clear that the M/s Kamakhya Udyog Pvt. Ltd vide their application dated 27.10.95 has applied for eligibility certificate stating themselves that the unit is a diversified unit. Hence their present contention that it should be treated as a new unit is a contradiction." 29. The committee also further noted that the same application dated 27.10.95 was verified by Project Manager DIC, Kamrup as diversified unit. However, the same General Manager DIG, Kamrup has registered the unit on 4.7.96 as separate unit. The committee accordingly felt that there was no merit in the application of M/s Kamakhya Udyog Pvt. Ltd. 30. The respondents contended that the petitioner's water tank unit has never been accepted by the Directorate as a new unit as it was not a new unit for such activity was included as additional item in its original registration certificate. Once the activity of manufacturing of water tank of the petitioner unit having been included in the original registration certificate as an additional item as early as in February, 1993 after due consideration, there was no case for issuance of another SSI registration for the same activity in the same unit having same power connection situated in the same plot of land owned by the petitioner unit. Moreover, the subsequent departmental enquiry proved that the water tank unit claimed to be a new unit by the petitioner, is nothing but a part of the original unit owned by the petitioner. 31. Proposal of the eligibility certificate of the said unit, according to Mr. KH Choudhury, was placed before the State Level Committee which was the apex expert committee for granting eligibility certificate and considering other technical aspect. 31. Proposal of the eligibility certificate of the said unit, according to Mr. KH Choudhury, was placed before the State Level Committee which was the apex expert committee for granting eligibility certificate and considering other technical aspect. After considering all aspect of the matter the said State Level Committee held that there was no merit in the application of M/s Kamakhya Udyog Pvt. Ltd for their being treated as a new unit and advised that the officer responsible should be asked to explain. Shri KH Choudhury, further submitted that these are the matter in the realm of policy and thus cannot be a subject matter of judicial review. In support of his contention learned counsel referred the decision Tata Iron & Steel Co. Ltd vs. Union of India & another, reported in (1996) 9 SCC 709 para 68,69. 32. The case discussed above namely, M/s Kamakhya Udyog Pvt. Ltd is purely a case based on facts. From the facts narrated above, it thus emerges that the State Level Committee consisting of experts assessed the merits of the case of the petitioner and refused to treat the water tank as part of new unit on analysis of the factual situation. The authority rightly applied its mind to the fact situation and therefore no infirmity had been caused and as such requiring interference from the Court in Article 226 of the Constitution accordingly liable to be dismissed and the same is accordingly dismissed. 33. So far as Civil Rule No.2382 of 1997, United Soft Drinks Pvt. Ltd is concerned it appears that authorisation certificate issued earlier was wrongly issued by providing full concession for the entire unit relying upon an authorisation certificate which was found to be irregular. The competent authority accordingly issued notice to show cause as to why necessary correction should not be made. The petitioner instead of showing show cause sought for time to reply the notice. The eligibility certificate was issued for the portion on which expansion was made and not for the whole unit. From the facts it appears that the unit already granted exemption for the period from 10.5.93 to 9.5.2000, no infirmity as such and accordingly, this petition is liable to be dismissed and the same is dismissed. 34. The eligibility certificate was issued for the portion on which expansion was made and not for the whole unit. From the facts it appears that the unit already granted exemption for the period from 10.5.93 to 9.5.2000, no infirmity as such and accordingly, this petition is liable to be dismissed and the same is dismissed. 34. Before dealing with the contentions of the other writ petitions it would be pertinent to refer the relevant provision of exemption introduced by the Assam General Sales Tax Act in section 9 and 74, which are as under : "9. Exemption: (1) Subject to the conditions and exceptions, if any, set out in Schedule the sales of goods specified therein shall be exempted from tax under this Act. (2) The State Govt. may by notification in the Official Gazette add to, amend or otherwise modify the said Schedule and thereupon the said Schedule shall be deemed to have been amended accordingly. (3) The State Govt. may by notification in Official Gazette make an exemption or reduction in rate in respect of any tax or interest payable under this Act on the sale or purchase of any class of goods specified therein. (1) at all or any specified point or points of sale in a series of sales by successive . dealers or (ii) by any specified class of persons in regard to the whole or any part of their turnover : Provided that any exemption or reduction may extend to the whole of the State or to any specified area or areas therein and be subject to such restrictions and conditions as may be specified in the notification : Provided further that validity of any notification issued under this sub-section shall not exceed a period of three years from the date of its issue. (4) The State Government may, from time to time by notification in the Official Gazette frame one or more schemes for the grant of relief to any class of industries within the State or within any specified part of the State on or after such date as may be specified in such scheme and producing such goods as may be specified therein by way of full or partial exemption of any tax payable under this Act on the raw materials or other input purchased by them within the State or on the manufactured goods sold by them within the State or in the course of inter-State trade or commerce for such period or periods as may be specified or by way of deferment of the tax payable by them under this Act for such period as may be specified and subject to such other restrictions and conditions as may be provided in such scheme or schemes. 74. Repeals and savings. (1) The following laws are hereby repealed : 1. The Assam Sales Tax Act, 1947 (Assam Act XVII of 1947). 2. The Assam Finance (Sales Tax) Act, 1956 (Assam Act XI of 1956). 3. The Assam (Sales of Petroleum and Petroleum Products including Motor Spirit and Lubricants) Taxation Act 1955 (Assam) Act IX of 1956). 4. The Assam Purchase Tax Act, 1967 (Assam Act XIX of 1967). (2) Notwithstanding the repeal of the aforesaid laws by this Act and save as otherwise provided in sub-section (3) all rules, notifications, registrations or other documents, forms and notice made or prescribed or issued thereunder which were in force immediately before the appointed day, and all proceedings for the assessment or reassessment of any dealer or persons in respect of such period may be taken or continued as if this Act had not been passed. (3) Notwithstanding anything contained in sub-section (2) in respect of the following matters relating to any period ending before the appointed day, the provisions of the Act shall apply to - (a) an appeal or application for refund, rectification or revision, in respect of any period ending before the appointed day, provided such appeal or application has been made and the time limit for such appeal or application has not expired before the appointed day: (b) any proceeding by way of rectification or revision in respect of any period ending before the appointed day provided the time limit for such rectification or revision has not expired before the appointed day; (c) any return, statement or account relating to any period ending before the appointed day which is delivered, furnished or produced on or after the appointed day or any proceeding has been taken under Chapter IX on or after the appointed day, (d) any tax, interest, penalty or other dues remaining unpaid on the appointed day; (e) any tax relating to any period ending before the appointed day which- is refundable on or after the appointed day, (f) any exemption of tax by way of grant of relief from any day prior to the appointed day." 35. By section 9 on the Act, the legislature authorised the State Govt. to provide for exemption or reduction in respect on any tax or interest payable under the Act on the sales of goods specified therein by notification in the Official Gazette, subject to the conditions and exceptions if any. The validity of the notification issued under sub-section (3) shall not exceed a period of three years from the date of its issue. Sub-section (4) of section 9, authorised the State Govt. The validity of the notification issued under sub-section (3) shall not exceed a period of three years from the date of its issue. Sub-section (4) of section 9, authorised the State Govt. to frame one or more scheme for the grant of relief to any class of industries within any specified part of the State on or after such date as may be specified in such scheme and producing such goods as may be specified therein by way of full or partial exemption of any tax payable under the Act on the raw materials or other input purchased by them within the State or on the manufactured goods sold by them within the State or in the course of inter State trade or commerce for such period or periods as may be specified or by way of deferment of the tax payable to them under this Act for such period as may be specified and subject to such other restrictions and conditions as may be provided in such schemes by way of notification in Official Gazette. 36. Section 74 is repealing and saving clause. Notwithstanding the repeal of the laws under sub-section (1) and anything contained in sub-section (2) the matters specified clauses (a) to (f) of sub-section (3) of this Act relating to any period ending before the appointed day the provision of this Act shall apply. Clause (f) of sub-section (3) enjoins that any exemption of tax by way of grant of relief from any date prior to the appointed date. The legislature in section 9 empower the State Govt. to make an exemption and reduction of rank and also framing of scheme for granting relief to any class of industry. Section 9 (3) therefore conferred a statutory power on the authority for making one or more scheme to grant relief to any class of industries within the State of Assam, under the Act for such period as may be specified and subject to such other restriction and conditions as may be provided in such scheme or schemes. The legislature therefore conferred upon the State Govt. to make appropriate scheme without fixing any limitation. The scheme made under sub-section (4) therefore is a statutory scheme which will be subject to the statutory limitation if there be any. 1995 Scheme is also a statutory Scheme for which there is no dispute at the Bar. 37. The legislature therefore conferred upon the State Govt. to make appropriate scheme without fixing any limitation. The scheme made under sub-section (4) therefore is a statutory scheme which will be subject to the statutory limitation if there be any. 1995 Scheme is also a statutory Scheme for which there is no dispute at the Bar. 37. In Civil Rule No. 1224 of 1997 (M/s SM Ispat Ltd. vs. State of Assam & others), the company at all relevant time was engaged in the business of manufacture and sale of galvanised and corrugated sheets. According to the petitioner, on the strength of 1991 Industrial Policy of the Govt., the petitioner-company undertook expansion, modernisation and diversification work in its industrial unit which was an existing unit in production. The Govt. of Assam by its notification dated 18.2.93 (Annexure IV to the writ petition) notified certain industries to be ineligible for availing the State Govt.'s incentives under the 1991 Industrial Policy which was made effective from 1.4.91. By the said notification, the units engaged in manufacture and sale of galvanised and corrugated sheets were also included under item No. 18 of the said notification. By another notification dated 26.4.94 (Annexure IVA to the writ petition), the Govt. of Assam in supersession of its earlier notification dated 18.2.93 declared certain industries to be non-priority industries for availing the incentives of the State Govt. under the 1991 Industrial Policy with effect from 11.3.94. Galvanised sheet and corrugated unit was also included under item 14 of the said notification. The notification dated 26.4.94 contained that industries specified in the said notification would avail incentives under the 1991 Industrial Policy on the terms and conditions that the Govt. of Assam would extend the benefits to the industries specified by the Govt. of Assam in the said notification. According to the petitioner, the company completed its expansion and diversification programmed much earlier to the issuance of the notification dated 26.4.94 and started commencement of the production with effect from 7.1.94 and was granted eligibility certificate by the appropriate authority dated 30.5.95 thereby granting exemption from sales tax from 7.1.94 to 6.1.2001. The scheme framed by the State Govt. by the way of notification under section 9 (4) of the 1993 Assam General Sales Tax Act, galvanised sheets and corrugated units were shown to be included in the category of industries not eligible for the benefit under the scheme. The scheme framed by the State Govt. by the way of notification under section 9 (4) of the 1993 Assam General Sales Tax Act, galvanised sheets and corrugated units were shown to be included in the category of industries not eligible for the benefit under the scheme. The legality of the action of the respondents was challenged in this proceeding on the ground that the company already undertook expansion and diversification work and started production on the strength of 1991 Policy and thus the impugned notification was hit by the doctrine of promissory estoppel. The petitioner-company challenged the validity of the provisions of the 1995 Scheme on the grounds common to those in the case of M/s Manjushree Extrusions Ltd vs. State of Assam & others (Civil Rule No. 3673 of 1996). 38. The State-respondents submitted their affidavit and denied and disputed the claim of the petitioner-company. According to the respondents, the petitioner-company was incorporated on 13.10.95. Earlier, the industry was known as Kamrup Industry which was a partnership firm and dissolved on 30.6.56 and the assets and liabilities of the said firm was taken over by Sree Kamrup Industry (Assam) Ltd. anew company which was incorporated on 27.3.96. The partnership firm as well as the company mentioned above were engaged in corrugation of plain sheet only and not engaged in galvanised and manufacturing work and therefore was not eligible for getting relief. 1995 Scheme being a statutory scheme declared that galvanised sheets and corrugation unit was not eligible for any benefit under the scheme. The respondents in their affidavit asserted that the existing units having availed of incentives will not be disqualified to get incentives for extra investment made for expansion, modernisation and diversification project. The respondents however denied that the petitioner-company provided required employment under the Industrial Policy to the specified class of people. According to the respondents, the petitioner-company also did not furnish necessary particulars while applying for issuance of eligibility certificate. The respondents pointed out to Annexure V to the writ petition which disclosed that the certificate was valid upto 6.1.96. The Eligibility Certificate No. BTC/K/(KC)/91/340/95-96 (SI. 017) dated 30.5.95 was granted to the Kamrup Industries (Assam) and not granted to the petitioner company and it was valid upto 6.1.96. The respondents pointed out to Annexure V to the writ petition which disclosed that the certificate was valid upto 6.1.96. The Eligibility Certificate No. BTC/K/(KC)/91/340/95-96 (SI. 017) dated 30.5.95 was granted to the Kamrup Industries (Assam) and not granted to the petitioner company and it was valid upto 6.1.96. The respondents denied the entitlement of the petitioner-company to claim exemption from payment of sales tax on raw materials and finished products for the period of 7 years. In the affidavit the respondents also stated-that in respect of any unit undergoing expansion, the concession of sales tax exemption under the 1991 Scheme was extended only for the expanded portion of unit and not for the entire unit, the original unit having already availed necessary benefit of sales tax exemption and subsidies. 39. From the narration of facts as indicated above, it appears that the writ petition contains serious disputed facts. The materials on record do not disclose any breach of promise. Doctrine of promissory estoppel has emanated from equity to avoid injustice. Granting of exemption on recession of tax emanated from legislative power which is to be used for the general good of the people. Exemption for tax can legitimately be granted on the public interest and it is in the public interest that it can be rescinded. All these aspects depend on the economic trend as well as the situation. There cannot be estoppel against a fiscal measure. I have given my anxious consideration on the matter. The petitioner-company in this case have failed to disclose any facts showing higher equity in their favour. Considering the overall facts situation, balance of equity and public interest, I do not find any illegality on the part of the respondents in withdrawing the exemption. 40. The State Govt. from time to time laid down its policy in respect if industrial development in the State. The petitioners in these .writ petition's do not have any grievance as regards the implementation of 1982 and 1985 Industrial Policies. Clause 1 of the 1991 Policy declared that the 1991 Incentive Scheme was to remain in operation for a period of 5 years commencing from 1.4.91 or till such time as the Govt. might consider fit and proper. 1st. The petitioners in these .writ petition's do not have any grievance as regards the implementation of 1982 and 1985 Industrial Policies. Clause 1 of the 1991 Policy declared that the 1991 Incentive Scheme was to remain in operation for a period of 5 years commencing from 1.4.91 or till such time as the Govt. might consider fit and proper. 1st. April, 1991 was described as effective date for the 1991 Incentive Scheme and from the said date the 1982 Incentive Scheme and the 1986 Incentive Scheme and other relevant industrial policy resolutions ceased to be operative unless specifically provided for. The industrial units which were already availing incentives eligibility certificate under those schemes were to continue to be governed by the 1982 Incentive Scheme and such units were described as 1982 continuing industries'. However, no fresh eligibility certificate was to be issued to any unit after the effective date of the 1991 Incentive Scheme. The units satisfying conditions of the 1982 Scheme but not possessing eligibility certificate were to be considered under the 1986 Incentive Scheme subject to the conditions that no further eligibility certificate would be issued to any industrial unit under the 1986 Incentive Scheme after 1.4.92. The industrial units' which were already availing incentives under the 1986 Incentive Scheme or had obtained eligibility certificate under the said scheme would continue to avail incentive under the said scheme and such units would be described as 1986 continuing industries'. But no application for issue of eligibility certificate was to be accepted after 30.9.91 and no further eligibility certificate was to be issued to any unit under the 1986 Scheme after 1.4.92. The 1991 Policy envisages that only new units set up on or after 1.4.91 and existing units undertaking expansion, modernisation or diversification at the same location or at any other place in the State of Assam were made eligible for incentives under the 1991 Scheme on the conditions specified in clauses 2.1,2.2 and 2.3. The Scheme defined 'new units' as well as 'existing units'. Clause 5 under Part II of the 1991 Scheme indicated that expansion/modernisation/diversification of an existing industrial unit, such unit would be eligible for all incentives if the total capital investment on plant and machinery in the expansion, modernisation or diversification, as the case may, was more than 25%of the total fixed capital investment of the existing unit. Clause 5 under Part II of the 1991 Scheme indicated that expansion/modernisation/diversification of an existing industrial unit, such unit would be eligible for all incentives if the total capital investment on plant and machinery in the expansion, modernisation or diversification, as the case may, was more than 25%of the total fixed capital investment of the existing unit. Gross-value of all the capital investment made on land, building, plant and machinery of an existing unit was to be taken into consideration for the purpose of calculation. Expansion, modernisation and diversification would imply and increase of atleast 25% in the existing installed capacity as well as increase of additional employment atleast by 10%. An existing unit that has availed itself of the incentives was not to disqualified for expansion, modernisation or diversification project to get incentives for the extra investment made. The 1991 Policy, therefore, conferred incentives between the new units as well as existing units. 1995 Scheme also maintained a distinction between a new industrial unit as well as existing units. An industrial unit which had completed all the initial, effective steps on or before 1.4.91 was to be considered as a new unit. The scheme also envisaged about those industrial units within the State of Assam which was in production at any time prior to 1.4.91 undertaking expansion/modernisation/ diversification to the minimum extent of 25% at the same location or any other places of the State of Assam and with an additional employment atleast by 10% and conformed to the criteria of employing the people of the State would also be treated as an eligible unit for the purpose of the scheme. 1995 Scheme further spelt out the meaning of expansion, modemisaton and diversification which envisioned 25.% of the total fixed capital investment of the unit prior to such expansion, modernisation and diversification. 1991 scheme also referred about increase of atleast 25% in the existing installed capacity as well as increase in the additional employment of atleast by 10%. 1995 Scheme further spelt out the meaning of expansion, modemisaton and diversification which envisioned 25.% of the total fixed capital investment of the unit prior to such expansion, modernisation and diversification. 1991 scheme also referred about increase of atleast 25% in the existing installed capacity as well as increase in the additional employment of atleast by 10%. Clause 7 of the 1995 Scheme introduced the mechanism of determination of increase in production of an industrial unit which undertook expansion/modernisation/diversification and for the above purpose the actual production of the unit during 365 consecutive working days of the unit preceding the date of completion of its expansion/modernisation/diversification had been described as base year production, and the actual production of an industrial unit after expansion, modernisation or diversification was to be determined on an yearly basis, the first being the 365 working days following the date of commencement of production after the completion of the expansion/ modernisation/diversification as the variables for determining the increase in production. Clause 11 of the 1995 Scheme prescribed the procedure for extension of benefit under the scheme to an eligible industrial unit under the category 'B' which obtained the certificate of authorisation on or after the date of issue of the notification dated 16.8.95 but whose certificate of authorisation was in force prior to the date of issue of the said notification dated 16.8.95 but from or after 1.4.91. The 1991 Policy which is referred in extenso envisaged for incentives to the existing units to the extent of expansion/modernisation/diversification. The 1991 Policy gives full incentives only the new units and sales-tax exemption for 7 years. 1991 Scheme was not meant for the existing industrial unit in its entirety but it conferred the benefit only to the extent of expanded portion. 1991 Policy therefore cannot be treated as a promise held out by the State Govt. not to realize sales-tax for a period of 7 years for the entire industrial unit. No such promise as such can be spelt out from the 1991 Policy. 1991 Incentive Policy taken care of the units to the extent of expansion/modernisation and diversification so far the existing units are concerned. The 1995 Sales Tax Concession Scheme was introduced by the State Government on the authority of sub-section (4) of section 9 of the Sales Tax Act, 1993. It empowered the State Govt. 1991 Incentive Policy taken care of the units to the extent of expansion/modernisation and diversification so far the existing units are concerned. The 1995 Sales Tax Concession Scheme was introduced by the State Government on the authority of sub-section (4) of section 9 of the Sales Tax Act, 1993. It empowered the State Govt. of frame one or more schemes for grant of relief to any class of industry within the State or within the specified part of the State by way of full or partial exemption of any tax payable under the Act on the raw materials or other input purchased within the State of Assam or on the manufactured goods sold within the State or in the course of inter-State trade or commerce for such period or periods as may be specified. 1995 Scheme therefore is statutory both in origin as well as in content. 41. As mentioned earlier, all the petitioner-companies enjoyed full benefit of sales-tax concession as per the 1982 and 1986 Industrial Policies. The 1991 Policy and for that matter the 1995 Concession Scheme conferred full incentives only to the new units set up on or after 1.4.91. All these petitioners are units set up before 1.4.91 and, therefore, they are only existing units. The 1991 Scheme only conferred benefit to the extent of expansion/modernisation or diversification. Sales Tax Concession Scheme, 1995 did not make any material departure from the 1991 Industrial Policy and incentives were only given to the existing units to the extent indicated above. The Legislature conferred wide power on the State Govt. to frame from time to time by notification scheme or schemes for grant of relief. No limitation as such was imposed by the State Govt.. In formulating a policy there was no inhibition imposed on the State Govt. by the Act in defining the limits of the concession. The Sales Tax Concession Scheme of 1995 like the 1991 Scheme also provided incentives to those industries undertaking expansion/ modernisation/diversification to the minimum extent of 25% and generating additional employment atleast 10% after fulfilling the criteria specified in the scheme. When an authority is empowered to formulate a scheme, the authority is also authorised to prescribe the minimum extent of expansion/modernisation/ diversification. Similarly, the executive authority is conferred full discretion for laying down the criteria for determination of increase in production after all incentives are given as per the scheme. When an authority is empowered to formulate a scheme, the authority is also authorised to prescribe the minimum extent of expansion/modernisation/ diversification. Similarly, the executive authority is conferred full discretion for laying down the criteria for determination of increase in production after all incentives are given as per the scheme. The main object of the scheme is for promotion of industrial growth as well as generation of employment. Growth therefore is linked with the productivity which is one of accepted principles for ascertaining the growth. 42. The petitioners herein already reaped the benefits of earlier scheme new units and neither under the 1991 Policy nor under the Concession Scheme of 1995 they are entitled to full incentives. 43. In view of the foregoing discussions, the principle of promissory estoppel does not come into play. The principle of promissory estoppel is a principle of equity. In the instant case, the petitioner-companies had already availed of the full concession and in such a situation there is no scope for applying the equitable principle of requisite estoppel. In absence of any entitlement of the petitioners for full benefit of sales tax concession under the scheme, the said benefit cannot be provided on the strength of eligibility certificate alone. The Sales Tax Concession Scheme of 1995 took care of the 1991 Policy. As a matter of fact there is no substantial difference between the 1991 Scheme and the 1995 Sales Tax Concession Scheme in content. Therefore, the 1995 Sales Tax Concession Scheme cannot be said to be retrospective in effect. The Sales Tax Concession Scheme, 1995 cannot be read as retrospective. The legislature gave full mandate to the executive authority to frame one or more scheme/schemes to grant relief to any class of industry from time to time by notification. In formulating its policy, the executive authority is within its right to indicate the criteria for determination of increase in production, as stated earlier, and the same cannot be said to be arbitrary and violative of Articles 14 and 19 (1) (g) of the Constitution of India. The right to get tax incentive is not a fundamental right. In formulating its policy, the executive authority is within its right to indicate the criteria for determination of increase in production, as stated earlier, and the same cannot be said to be arbitrary and violative of Articles 14 and 19 (1) (g) of the Constitution of India. The right to get tax incentive is not a fundamental right. Right guaranteed under Article 19 (1) (g) of the Constitution is the right to practise any profession or to carry on any occupation trade or business limiting the right of the existing industrial units in getting the sales tax concession and as the petitioners herein have already reaped the benefits of earlier scheme as new units it cannot be held that there has been violation of Article 14 and 19 (1) (g) of the Constitution of India, and I do not find any illegality on the part of the respondents in withdrawing the sales tax exemption. 44. For the reasons stated above, the writ petitions stand dismissed with costs of Rs.2000/-each.