Judgment Ramanujam, J.: These two appeals have been filed against the judgments rendered by Padmanabhan, J. in Writ Petition No.1794/81 and Mohan, J. in W.P.1896/31. The first writ appeal viz. W.A.No.529/83 lias been filed by respondents 4 to 7 in the Writ Petition No.1896/81 and the second writ appeal viz. W.A.No.-575/83 has been filed by the 2nd respondent in the writ petition 1794 of 1981. 2. The circumstances under which the above writ petitions came to be filed before this court against respondents 1 and 2 therein representing the Tamil Nadu Water Supply and Drainage Board, hereinafter referred to as the “Board” for the issue of a writ of declaration declaring proviso 2 to Rule 19(2)(b) of the Tamil Nadu Water Supply and Drainage Board Service Rules as ultra vires and unconstitutional in so far as the petitioners are concerned are these: They possess Diploma and Licentiate in Sanitary Engineering and Civil Engineering of the Directorate of Technical Education, Madras. There are two feeder categories from which promotion is made to the post of Assistant Executive Engineers. One is the category of Assistant Engineers who are degree holders whereas junior engineers are diploma holders. The petitioners belonged to the latter category. Once the persons are promoted as Assistant Executive Engineers from the above two feeder categories, they got merged into one category namely, Assistant Executive Engineers. The responsibilities and the nature of work as also the emoluments are the same and there is no differentiation thereafter. After the petitioners were promoted as Assistant Executive Engineers, a common seniority list was published on 24-4-1980. In that list, the writ petitioners were sufficiently seniors to be considered for promotion as Executive Engineers. However, since the petitioners were not promoted as Executive Engineers even though their juniors have been promoted, they made representations to the Board to the effect that they had to be promoted before their juniors are promoted but they were told that they could be considered for promotion only if they are of exceptional merit and ability as provided in the proviso to Regulation 19(2)(b) of the Board's Service Regulations, 1972. It is at this stage the petitioners have come before this court, seeking a declaration that the proviso to Regulation 19(2)(b) is invalid and for directing the respondents in the writ petitions to promote the petitioners ignoring the above alleged invalid provision in the Regulations. 3. It is at this stage the petitioners have come before this court, seeking a declaration that the proviso to Regulation 19(2)(b) is invalid and for directing the respondents in the writ petitions to promote the petitioners ignoring the above alleged invalid provision in the Regulations. 3. In the counter affidavit filed by the Board in both the writ petitions, it has been averred that the promotions to the post of Executive Engineers are governed by Regulation 19(2) and Regulation 23 of the Board's Service Regulations and since the petitioners are diploma holders they cannot be promoted unless they are of exceptional merit and ability and the Board after considering the petitioners’ cases did not find them to be of persons of exceptional merit and ability and as such they were not promoted, that such a provision requiring diploma holders to be of exceptional merit and ability so as to enable them, to give promotions has not been introduced for the first time but has been in existence in the Public Health Engineering and Municipal Engineering Service from which the petitioners originally came and the Board's Regulations merely continue the same. According to the Board, Regulation No.19(2)(b) does not violate either Article 14 or Article 16 of the Constitution as contended by the writ petitioners. It is also pointed out by the Board that Regulation 23 prescribes the qualification and so long as the Board has got the power to prescribe the qualifications for the posts of Executive Engineers, neither Regulation 23 nor the proviso to Regulation 19(2)(b) could be successfully questioned. 4. Padmanabhan, J. before whom Writ Petition No.1794/81 came up for disposal held that though the petitioner herein was a diploma holder, once degree holders and diploma holders are appointed as Assistant Executive Engineers and treated alike both in respect of their duties as well as salary, no discrimination could be made between the two categories with reference to the subsequent promotion to the post of Executive Engineers and that since the proviso to Regulation 19(2)(b) discriminates the Assistant Executive Engineers who are diploma holders it has to be struck down. In that view the learned Judge allowed the writ petition and directed the Board to consider the claim of the petitioner in that writ petition for promotion as Executive Engineer on a par with others without reference to the second proviso to Regulation 19(2)(b). In that view the learned Judge allowed the writ petition and directed the Board to consider the claim of the petitioner in that writ petition for promotion as Executive Engineer on a par with others without reference to the second proviso to Regulation 19(2)(b). Writ Petition No.1896 of 1981 came up for final disposal before Mohan, J. and the learned Judge has followed and applied the said decision of Padma-nabhan, J. rendered in Writ Petition No.1794/81. Thus the view taken by Padmanabhan, J. has been questioned in these writ appeals by the Board on the one hand and persons who are likely to be affected by giving effect to the order of Padmanabhan, J. on the other. 5. To appreciate the contentions advanced by both sides, it is necessary to have an idea of the relevant Regulations. Section 73 of the Tamil Nadu Water Supply and Drainage Board Act, hereinafter referred to as the Act, 1970 enables the Board to make Regulations with the previous approval of the State Government. In exercise of the power under section 73 the Board has made the Tamil Nadu Water Supply and Drainage Board Service Regulations, 1972, hereinafter referred to as the Service Regulations with effect from 14-4-1971. Regulation 5 constitutes five different services Tamil Nadu Water Supply and Drainage Board (1) General Service, (2) Engineering Service, (3) Engineering Subordinate Service, (4) Subordinate Service and (5) Last Grade Service. We are concerned here with the Engineering Service and this consists of the following 9 categories viz. (1) Chief Engineer, (2) Superintending Engineers, (3) Executive Engineers (including Deputy Engineers), (4) Assistant Water Analyst (8) Assistant Geologist and (9) Geological Assistant. Regulation 9(4) deals with the promotion to the post of Executive Engineers and Superintending Engineers. It provides that the Chief Engineer of the Board shall prepare a list of all eligible candidates arranged in the order of seniority for consideration having regard to their efficiency-cum-seniority showing in the list their names, present designation, present pay, age, qualifications and experience and forward the same to the Managing Director with their confidential reports, and the Managing Director after scrutinising the list and the confidential reports will make his recommendations to the Board for selection, and after selection by the Board, the Managing Director will issue necessary orders. Regulation 19(2) deals with the appointment to the various categories in the Board's Engineering Service. Regulation 19(2) deals with the appointment to the various categories in the Board's Engineering Service. Promotion to the posts of Executive Engineers is from Assistant Engineers and promotion to the posts of Assistant Engineers is either by direct recruitment or by promotion from Junior Engineers or Supervisors. Regulation 19(2)(b) says that the posts of Chief Engineer, Superintending Engineers and Executive Engineers shall be selection posts and promotions to these posts shall be made on grounds of merit and ability, seniority being considered only where merit and ability are approximately equal. However, there is a proviso to Regulation 19(2)(b) which is to the following effect: “Provided that an Assistant Engineer possessing the Upper Subordinate or Licentiate in Civil Engineering Diploma of the College of Engineering, Guindy or of State Board of Technical Education and Training, Madras, should not be eligible for promotion to the post of Executive Engineer unless he has shown exceptional merit in his work.” It is the scope of the above proviso to Regulation 19(2)(b) which has now come up for consideration. Regulation 23 prescribes the requisite qualifications for various categories of persons in the Board's Service. The qualifications set out therein for the post of Executive Engineer are as follows: (i) Must be an approved probationer in the service as Assistant Engineer; (ii) Must have rendered service as Assistant Engineer for not less than (a) five years if recruited by transfer; or (b) six years if recruited direct; and (iii) Must possess a degree in Engineering (Civil or Mechanical) of any University or Institution recognized by the University Grants Commission for the purpose of its grant; or A diploma in Civil or Mechanical Engineering of the College of Engineering, Guindy or Licentiate in Civil Engineering, Licentiate in Sanitary Engineering or Diploma in Civil Engineering of the State Board of Technical Education and Training, Madras. Provided in the case of Diploma holders those with exceptional merit and ability alone shall be considered for promotion.” It is in the light of these Regulations, the rival contentions of the parties in this case have to be considered. Provided in the case of Diploma holders those with exceptional merit and ability alone shall be considered for promotion.” It is in the light of these Regulations, the rival contentions of the parties in this case have to be considered. According to the writ petitioners, though it is true that the petitioners as diploma holders were originally appointed as Junior Engineers, and were later promoted as Assistant Executive Engineers, while degree holders were directly recruited as Assistant Engineers and then later on promoted as Assistant Executive Engineers, once they are appointed as Assistant Executive Engineers and integrated into one category, no further distinction could be made as between degree holders and diploma holders in the matter of further promotion and any discrimination at that stage based on the educational qualifications will clearly offend Articles 14 and 16 of the Constitution. According to them as Assistant Executive Engineers, both the degree holders as well as diploma holders discharge the same functions and receive the same salary and there is absolutely no distinction between them. Therefore, for purposes of promotion there could not be any differentiation between the degree holders and diploma holders taking into account the source from which their promotion was made. In support of their contention, the writ petitioners have strongly relied on the decision of the Supreme Court in ROSHAN LAL v. UNION OF INDIA ROSHAN LAL v. UNION OF INDIA (1968)1 S.C.J.746= (1968)1 S.C.R.185= A.I.R.967 S.C.1889 and state that the decision of Padmanabhan, J. is quite in accord with the view expressed by the Supreme Court in the said case. 6. On the other hand, on behalf of the appellants it is contended that for purposes of promotion the educational qualification is the relevant criterion and that even from among the members of the same service, promotion could be made taking into account the educational qualifications possessed by them and that it cannot be said in all casps that once people from various sources are brought under one category no distinction could be made between degree holders and diploma holders. It is further contended on behalf of the appellants, that similar rules for promotion to the posts of Executive Engineers were in existence even before the framing of the Regulations and that, therefore, the Regulations do not make any departure in the position that existed before the framing of the Regulations and hence the writ petitioners cannot have any tenable grievance against the impugned Regulations. In support of their contentions, reference has been made to the decision in STATE OF JAMMU AND KASHMIR v. TRILOKI NATH KOSHLA AND OTHERS STATE OF JAMMU AND KASHMIR v. TRILOKI NATH KOSHLA AND OTHERS (1974)1 S.C.J. 366= (1974)1 S.C.C.19= A.I.R.1974 S.C.I and A.K.B.NAMBIAR v. STATE OF KERALA A.K.B.NAMBIAR v. STATE OF KERALA (1979) Lab.I.C.894. 7. The question of classification on the basis of educational qualifications came to be considered by the Supreme Court in STATE OF MYSORE v. NARASING RAO STATE OF MYSORE v. NARASING RAO (1968)1 S.C.R.407: (1968)1 S.C.J. 863= A.I.R.1968 S.C.349; GANGA RAM v. UNION OF INDIA GANGA RAM v. UNION OF INDIA (1970)3 S.C.R.481: (1970)2 S.C.J.584= A.I.R.1970 S.C.2178; THE UNION OF INDIA v. DR (MRS) S.B.KOHLI THE UNION OF INDIA v. DR (MRS) S.B.KOHLI (1973)2 S.C.C.592= (1973) Lab.I.C.423= A.I.R.1973 S.C.811 and in all those cases the classification was upheld. In STATE OF MYSORE v. NARA-SING RAO STATE OF MYSORE v. NARA-SING RAO (1968)1 S.C.R.407: (1968)1 S.C.J.863= A.I.R.1968 S.C.349 the tracers doing equal work were classified into two grades having unequal pay, the basis of the classification being higher educational qualifications. In (1970)3 S.C.R.481: (1970)2 S.C.J.584 the court held that it is open to the State to lay down conditions of efficiency and other qualifications for securing best services for being eligible for promotion in its departments. In (1973)3 S.C.C.592= (1973) Lab.I.C.423= A.I.R.1973 S.C.811 the rule requiring that a Professor in Orthopaedics must have a post-graduate degree in the particular speciality was upheld on the ground that the classification made on the basis of such a requirement was not without reference to the. objectives sought to be achieved and there can be no question of discrimination. In that case the argument that a degree qualification was not the only criterion of suitability was rejected as strange. objectives sought to be achieved and there can be no question of discrimination. In that case the argument that a degree qualification was not the only criterion of suitability was rejected as strange. Then came the decision in STATE OF JAMMU AND KASHMIR v. TRILOKI NATH KHOSLA AND OTHERS STATE OF JAMMU AND KASHMIR v. TRILOKI NATH KHOSLA AND OTHERS (1974)1 S.C.J.366= A.I.R.1974 S.C.I wherein the Supreme Court affirmed the view taken in the above three cases and held that a classification made on the basis of educational qualification was valid. In that case the Jammu and Kashmir Engineering (Gazetted) Service Recruitment Rules, 1970 classified Assistant Engineers on the basis of educational qualifications for purpose of promotion as Executive Engineers. The question arose whether such a classification was violative of Articles 14 and 16 of the Constitution. The rules provided that only those Assistant Engineers who possessed a degree in Engineering shall be eligible for promotion as Executive Engineer thus rendering the diploma holders in engineering who are working as Assistant Engineers ineligible for promotion as Executive Engineers. The High Court took the view that the impugned rule restricting the promotion only to those Assistant Engineers who are diploma holders was violative of Articles 14 and 16 of the Constitution and when the matter went before the Supreme Court, it was contended on behalf of the State that the employees can, in the matter of promotion, be classified into different classes, of promotion, be classified into different classes on the basis of any intelligible differentia as for example, educational qualifications which has a nexus with the object of the classification, namely, officiency in the post of promotion. The said contention was upheld by the Supreme Court. The said contention was upheld by the Supreme Court. According to the Supreme Court though the persons appointed directly or by promotion were integrated into a common class of Assistant Engineers, they could, for purposes of promotion to the cadre of Executive Engineers be classified on the basis of educational qualifications, and that the rule providing that graduates shall be eligible for such promotion to the exclusion of diploma holders did not violate Articles 14 and 16 of the Constitution, and that as such a classification is made with a view to achieve administrative efficiency in the engineering service, the classification is clearly correlated, to it, for, higher educational qualifications are at least presumptive evidence of a higher mental equipment and the courts have always recognised educational qualifications as a safe criteria for determining the validity of a classification. The above decision clearly lays down that fixation of an educational qualification for purpose of promotion even if it is likely to affect some of the persons in the feeder category who do not have that educational qualification will have to be held to be valid for the educational qualification is a relevant criterion for making a classification with a view to secure efficiency of service. 8. In ROSHAN LAL v. UNION OF INDIA ROSHAN LAL v. UNION OF INDIA (1968)1 S.C.R.185=(1968)1 S.C.J.746=A.I.R.1967 S.C.1889 the Supreme Court considered a question which is similar to the one arising here. In that case the Railway Board issued a notification providing that 80% of the vacancies in Grade C would be filled up from the class of apprentice trainee examiners recruited on and after April 1, 1966 and the remaining 20% from amongst the train examiners in Grade D. It also provided that the apprentice trainee examiners who are absorbed in Grade D before April 1, 1966 would be accommodated in Grade C in the 80% of the vacancies reserved for them without undergoing any selection. Roshan lal Tandao who was a skilled artisan who was later selected and confirmed in Grade D as a train examiner challenged the said notification in so far as the notification gave a favourable treatment in regard to apprentice train examiners who had already been absorbed in Grade D. His case was that he along with other direct recruits formed one class in Grade D and according to the conditions of service applicable to them seniority was to be reckoned from the date of appointment as train examiners Grade D and promotion to Grade C was to be on the basis of the seniority cum suitability, irrespective of the source of recruitment and so long as he has been integrated with others in Grade D who came by direct recruitment no differentiation could be made as between him and the direct recruits in the matter of promotion to Grade C. The said Constitutional objection was upheld by the Supreme Court with these observations: “At the time when the petitioner and the direct recruits were appointed to Grade D there was one class in Grade D formed of direct recruits and the promotees from the grade of artisans. The recruits from both the sources to Grade D were integrated into one class and no discrimination could thereafter be made in favour of recruits from one source as against the recruits from the other source in the matter of promotion to Grade C. To put differently, once the direct recruits and promotees are absorbed in one cadre, they form one class and they cannot be discriminated for the purpose of further promotion to the higher grade C. In the present case, it is not disputed on behalf of the first respondent that before the impugned notification was issued there was only one rule of promotion for both the departmental promotees and the direct recruits and that rule was seniority-cum-suitability, and there was no rule of promotion separately made for application to the direct recruits. As a consequence of the impugned notification a discriminatory treatment is made in favour of the existing Apprentice Train Examiners who have already been absorbed in Grade D by March 31, 1966, because the notification provides that this group of Apprentice Train Examiners should first be accommodated en bloc in grade C upto 80 per cent of vacancies reserved for them without undergoing any selection. As regards the 20 per cent of the vacancies made available for the category of Train Examiners to which the petitioner belongs the basis of recruitment was selection on merit and the previous test of seniority-cum-suitability was abandoned. In our opinion, the present case falls within the principle of the recent decision of this court in Mervyn v. Collector (1966)3 S.C.R.600= (1967)1 S.G.J.574= A.I.R. 1967 S.C.52. From the above observations it will be clear that in the matter of promotional opportunities to Grade C no discrimination could be made between promotees and direct recruits by reference to the source from which they were drawn, and no favourite treatment could be given to the direct recruits in Grade D as against promotees to Grade D. Thus (1968)1 S.C.J.746: (1968)1 S.C.R.185 lays down that direct recruits and promoties lost their birthmarks on fution into a common stream of service and they cannot therefore be treated differently by reference to the consideration that they were recruited from different sources and that once they are integrated into a common class to make them equals, by making a classification cannot make them unequal again. The view taken in (1968)1 S.C.J.746 has been reiterated in MOHD SHUJAR All v. UNION OF INDIA MOHD SHUJAR All v. UNION OF INDIA (1975)1 S.C.R.449= A.I.R.1974 S.C.1631. In that case the Supreme Court after considering its earlier decisions observed: “Now, there are three decisions of this court where educational qualifications have been recognised as forming a valid basis for classification. In State of Mysore v. Narasing Rao of Mysore v. Narasing Rao (1968)1 S.C.J.863= (1968)1 S.C.R.407= A.I.R.1968 S.C.349= (1968) Lab.I.C.360 this court held that higher educational qualifications such as success in SSLC examination are relevant considerations for fixation of higher pay scale for tracers who have passed the SSLC examination and the classification of two grades of tracers in Mysore State one for matriculate tracers with higher pay scale and the other for non-matriculate tracers with lower pay scale, cannot be said to be violative of Article 14 or 16. So also in Union of India v. Dr, (Mrs) S.B.Kohli Union of India v. Dr, (Mrs) S.B.Kohli (1974)2 S.C.J.250= (1973)3 S.C.R.117= (1973)3 S.C.C.592= A.I.R.1973 S.C.811= (1973) Lab.I.C.423 a Central Health Service Rule requiring that a Professor in Orthopaedics must have a post graduate degree in particular speciality was upheld on the ground that the classification made on the basis of such a requirement was not ‘without reference to the objectives sought to be achieved and there can be no question of discrimination.” A very similar question arose in (1974)1 S.C.J.366= (1974)1 S.C.C.19= A.I.R.1974 S.C.1= (1974) Lab.I.C.1 where a rule which provided that only degree holders in the cadre of Assistant Engineers shall be entitled to be considered for promotion in the next higher cadre of Executive Engineers and diploma holders shall not be eligible for such promotion was challenged as violative of the equal opportunity clause. The Court repelled the challenge holding that ‘though persons appointed directly and by promotion were integrated into a common class of Assistant Engineers, they could, for the purposes of promotion to the cadre of Executive Engineers, be classified on the basis of educational qualifications’ and ‘the rule providing that graduates shall be eligible for such promotion to the exclusion of diploma holders’ was not obnoxious to the fundamental guarantee of equality and equal opportunity. But from these decisions it cannot be laid down as an invariable rule that whenever any classification is made on the basis of variant educational qualifications, such classification must be held to be valid, irrespective of the nature and purpose of the classification or the quality and extent of the differences in the educational qualifications. It must be remembered that ‘life has relations not capable always of division into inflexible compartments’ The moulds expand and shrink. The test of reasonable classification has to be applied in each case on its peculiar facts and circumstances. It may be perfectly legitimate for the administration to say that having regard to the nature of the functions and duties attached to the post, for the purpose of achieving efficiency in public service, only degree holders in engineering shall be eligible for promotion and not diploma or certificate holders. That is what happened in (1974)1 S.C.J.366= (1974)1 S.C.C.19= A.I.R. 1974 S.C.1= (1974) Lab.I.C.1 and a somewhat similar position also obtained in (1974)2 S.C.J.250= (1973)3 S.C.R.117= (1973)3 S.C.C.592= A.I.R.1973 S.C.811: (1973)1 Lab.I.C.423. That is what happened in (1974)1 S.C.J.366= (1974)1 S.C.C.19= A.I.R. 1974 S.C.1= (1974) Lab.I.C.1 and a somewhat similar position also obtained in (1974)2 S.C.J.250= (1973)3 S.C.R.117= (1973)3 S.C.C.592= A.I.R.1973 S.C.811: (1973)1 Lab.I.C.423. But where graduates and non-graduates are both regarded as fit and, therefore eligible for promotion, it is difficult to see now, consistently with the claim for equal opportunity, any differentiation can be made between them by laying down a quota of promotion for each and giving preferential treatment to graduates over non-graduates in the matter of fixation of such quota. The result of fixation of quota of promotion for each of the two categories of Supervisors would be that when a vacancy arises in the post of Assistant Engineer, which, according to the quota is reserved for graduate Supervisors, a non-graduate Supervisor cannot be promoted to that vacancy, even if he is senior to all other graduate Supervisors and more suitable than they. His opportunity for promotion would be limited only to vacancies available for non-graduate Supervisors. That would clearly amount to denial of equal opportunity to him. When there is a vacancy ear-marked for graduate Supervisor, a non-graduate Supervisor would be entitled to ask: ‘I am senior to the graduate Supervisor who is intended to be promoted. I am more suitable than he is. It is no doubt true that I am a non-graduate, but my not being a graduate has not been branded as a disqualification. I am regarded fit for promotion and, like the graduate Supervisor, I am equally eligible for being promoted. My technical equipment supplemented by experience is considered adequate for discharging the functions of Assistant Engineer.. Then why I am being denied the opportunity for promotion and the graduate Supervisor is preferred? ‘There can be no satisfactory answer to this question. It must be remembered that many of these non-graduate Supervisors might not have been able to obtain degree in engineering becasue they came from poorer families and did not have the financial resources to pursue degree course in engineering and not because they lacked the necessary capacity and intelligence. ‘Chilly penury’ might have ‘repressed their noble rage’. It must be remembered that many of these non-graduate Supervisors might not have been able to obtain degree in engineering becasue they came from poorer families and did not have the financial resources to pursue degree course in engineering and not because they lacked the necessary capacity and intelligence. ‘Chilly penury’ might have ‘repressed their noble rage’. It is of the essence of equal opportunity for such persons with humble and depressing backgrounds that they should have opportunity, through experience or self-study, to level up with their more fortunate colleagues who, by reason of favourable circumstances, could obtain the benefit of higher education, and if they prove themselves fit and more suitable than others, why should they be denied an opportunity to be promoted in a vacancy on the ground that that vacancy belongs to Supervisors possessing higher educational qualifications. As pointed out by Krishna Iyer, J. in (1974)1 S.C.J.366= (1974)1 S.C.C.19= A.I.R. 1974 S.C.1= (1974) Lab.I.C.I ‘the soul of Article 16 is the promotion of the common man's capabilities, over-powering environmental adversities and openime up full opportunities to develop in official life without succumbing to the sophistic argument of the elite that talent is the privilege of the few and they must rule’. To permit discrimination based on educational attainments not obligated by the nature of the duties of the higher post is to stifle the social thrust of the equality clause. A rule of promotion which, while conceding that non-graduate Supervisors are also fit to be promoted as Assistant Engineers, reserves a higher quota of vacancies for promotion for graduate Supervisors as against non-graduate Supervisors would clearly be calculated to destroy the guarantee of equal opportunity. But even so, we do not think we can be persuaded to strike down the Andhra Pradesh Rules in so far as they make differentiation between graduate and non-graduate Supervisors. This differentiation is not something brought about for the first time by the Andhra Pradesh Rules. It has always been there in the Engineering Services of the Hyderabad and the Andhra Pradesh States. The graduate Supervisors have always beep treated as a distinct and separate class from non-graduate Supervisors both under the Hyderabad Rules as well as the Andhra Rules and they have never been integrated into one class. It has always been there in the Engineering Services of the Hyderabad and the Andhra Pradesh States. The graduate Supervisors have always beep treated as a distinct and separate class from non-graduate Supervisors both under the Hyderabad Rules as well as the Andhra Rules and they have never been integrated into one class. Under the Hyderabad Rules , the pay scale of graduate Supervisors was Rs.176-300, while that of non-graduate Supervisors was Rs.140-300, and similarly under the Andhra Rules the pay scale of non-graduate Supervisors was Rs.100-250, but graduate Supervisors were started in this pay scale at the rate of Rs.150/- so that their pay was Rs.150-250. Graduate Supervisors and non-graduate Supervisors were also treated differently for the purpose of promotion under both sets of Rules. In fact, under the Andhra Rules a different nomenclature of Junior Engineers was given to graduate Supervisors. The same differentiation into two classes also persisted in the reorganised State of Andhra Pradesh. The pay scale of Junior Engineers was always different from that of non-graduate Supervisors and for the purpose of promotion, the two categories of Supervisors were kept distinct and apart under the Andhra Rules even after the appointed day. The common gradation list of Supervisors finally approved by the Government of India also consisted of two parts, one part relating to Junior Engineers and the other part relating to non-graduate Supervisors. The two categories of Supervisors were thus never fused into one class and no question of unconstitutional discrimination could arise by reason of differential treatment being given to them. Contention E cannot, therefore, prevail and must be rejected. We are of the view that the facts of this case attract the decisions of the Supreme Court in (1968)1 S.C.R.185= (1968)1 S.C.J.746= (1975)1 S.C.R.449= A.I.R.1974 S.C.1631. The other judgments of the Supreme Court which have been relied on by the learned counsel for the appellants merely related to fixation of an educational qualification for the promotional post, and that was challenged on the ground that it is likely to result in a classification of two categories, one having a higher educational qualification and the other having a lower educational qualification. That contention was rejected and the fixation of educational qualification was upheld on the ground that it had a nexus with the object sought to be achieved and that educational qualification is always a relevant criterion for making a classification. That contention was rejected and the fixation of educational qualification was upheld on the ground that it had a nexus with the object sought to be achieved and that educational qualification is always a relevant criterion for making a classification. But that principle will not apply to the facts of this case where there is no fixation of an educational qualification as such. Here according to Regulation 19(2)(b) and Regulation 23 both degree holders and diploma holders are entitled to be considered for promotion. But so far as diploma holders are concerned, they must be of exceptional merit and ability. Such a requirement cannot be said to be an educational qualification. When the main part of the said Regulations proceed on the basis that both degree holders and diploma holders are qualified to be considered for promotion as Executive Engineers, the proviso says that diploma holders cannot be promoted as Executive Engineers unless they are of exceptional merit and ability. Thus according to the said Regulations while degree holders can be promoted on the basis of merit and ability seniority being equal, diploma holders can be promoted only if they had shown exceptional merit and ability. Apart from the fact that there are no indications as to how exceptional merit and ability of a candidate could be gauged or assessed, the fact remains that after having considered them under the main part of the Regulations to be equals for the purpose of promotion, the proviso in so far as it imposes a further condition that the diploma holders should be of exceptional merit and ability makes them unequals. As already stated Regulation 19(2)(b) says that the posts of Executive Engineers shall be selection posts and promotion to those posts shall be made on grounds of merit and ability, seniority being considered only if merit and ability are approximately equal. As already stated Regulation 19(2)(b) says that the posts of Executive Engineers shall be selection posts and promotion to those posts shall be made on grounds of merit and ability, seniority being considered only if merit and ability are approximately equal. Regulation 23 says that for a person to be promoted as an Executive Engineer, he must have the following qualifications: (i) Must be an approved probationer in the service as Assistant Engineer; (ii) Must have rendered service as Assistant Engineer for not less than (a) five years if recruited by transfor; or (b) six years if recruited direct; and (iii) Must possess a degree in Engineering (Civil and Mechanical) of any University or Institution recognized by the University Grants Commission for the purpose of its grant; or A diploma in Civil or Mechanical Engineering of the College of Engineering, Licentiate in Sanitary Engineering or Diploma in Civil Engineering of the State Board of Technical Education and Training, Madras. Provided in the case of Diploma holders those with exceptional merit and ability alone shall be considered for promotion.” Thus a diploma in civil engineering is also treated as a sufficient qualification for promotion as Executive Engineer. Thus the main part of the Regulation 23 treats degree holders as well as diploma holders alike in the matter of promotion. However, the proviso to Regulation 23 says that in the case of diploma holders those with exceptional merit and ability alone shall be considered for promotion. In this connection, a reference to Regulation 9(4) will be apposite. That rule says that for purposes of promotion to the posts of Executive Engineers, a list of all eligible candidates arranged in the order of seniority having regard to their efficiency-cum-seniority showing the names of persons, present designation, present pay, age, qualifications and experience shall be prepared and forwarded for the approval of the Board. Thus this provision shows that once the degree holders who are Assistant Engineers and diploma holders who are Junior Engineers were recruited as Assistant Executive Engineers, the former by direct recruitment and the latter by promotion, they are integrated into one service having a common seniority list prepared for purposes of further promotion as Executive Engineers. Thus this provision shows that once the degree holders who are Assistant Engineers and diploma holders who are Junior Engineers were recruited as Assistant Executive Engineers, the former by direct recruitment and the latter by promotion, they are integrated into one service having a common seniority list prepared for purposes of further promotion as Executive Engineers. As already stated, the main Regulation 19(2)(b) and Regulation 23 having treated all assistant Executive Engineers whether they are diploma holders or degree holders alike and having given them the chance for promotion by assuring them that there will be a selection to the posts of Executive Engineers, having regard to merit and ability, the diploma holders alone cannot be segregated and a further condition imposed on them that they should possess exceptional merit and ability for the purpose of getting promotion as Executive Engineers. Thus, the main part of the regulation treats all Assistant Executive Engineers whether they are degree holders or diploma holders as equals in the matter of promotion, the proviso makes them unequal and such a classification is not with reference to any educational qualification. As already stated, a degree in Engineering and a diploma in Engineering are both treated as sufficient qualification for the post of Executive Engineer. It is only with reference to merit a distinction is made between degree holders and diploma holders; the degree holders have to merely exhibit merit and ability while the diploma holders have to exhibit exceptional merit and ability. This classification which is not based on educational qualification clearly offends Articles 14 and 16 for both the degree holders and diploma holders have been integrated into one service of Assistant Executive Engineers having a common seniority list and no distinction should be made except in the matter of educational qualification and here the distinction has been made which is clearly discriminatory. In this view of the matter, we are inclined to agree with the view taken by Padmanabhan, J. The writ appeals therefore fail and are dismissed. There will, however, be no order as to costs. Appeal dismissed.