JUDGMENT : A. Pasayat, J. - These writ applications Involve identical dispute, and therefore, are disposed of by this common judgment which 6hali govern each one of them. Petitioner has moved the Court for stay of realisation of demands raised under the Orissa Sales-tax Act, 1947 (in short, the 'Act') for the quarters ending 31-12-1984 and 31-3-1985 and assessment years 1986-86 and 1986-87. The Sales Tax Officer, Ward-A, Koraput-1 Circle, Jeypore being of the view that the petitioner was executing works contract, levied tax and total demand raised for the aforesaid various end years including those raised under the Orissa Additional Sales tax Rules, 1975 (in short, the 'Rules') come to Rs. 37.27,525/-, Since petitioner's challenge to the assessment did not yield any fruitful result before the appellate authorities, applications were field u/s 24(1) of the Act. Undisputedly references have been made to this Court and they are pending. During pandency of reference applications, petitioner moved the Orissa Sales Tax Tribunal (in short, the 'Tribunal') for stay. As these applications were not disposed of, petitioner has moved this Court for interference in the present writ applications. 2 A dispute was raised by the Revenue about maintainability of application for stay before the Tribunal. Making an elaborate analysis of the provisions contained in Section 24(7) of the Act, a Full Bench of this Court has held that the Tribunal has no jurisdiction to stay recovery of the amounts due under the orders of the Tribunal pending application for reference before the Tribunal or High Court u/s 24 of the Act. Full Bench, however, did not consider it necessary to decide the question whether writ applications would lie because that question was not before the Full Bench. In Commissioner of Income Tax Vs. Bansi Dhar and Sons, it was held that High Court in appropriate cases can deal with the applications for stay in exercise of powers conferred under Art. 226 of the Constitution of India, 1950 during pendency of reference or application therefore in terms of Section 24 of the Act. That is how we have taken up these writ applications for consideration. 3. Stand of petitioner in these writ applications in support of the plea for stay of realisation of the extra demands Is that nature of work executed by petitioner cannot be construed to be a works contract and there is no liability to pay tax under the Act. That is how we have taken up these writ applications for consideration. 3. Stand of petitioner in these writ applications in support of the plea for stay of realisation of the extra demands Is that nature of work executed by petitioner cannot be construed to be a works contract and there is no liability to pay tax under the Act. On account of non-payment of amounts after disposal of appeals by the Tribunal, penalty u/s 13(5) of the Act has been imposed. Petitioner's stand is that it had no knowledge about disposal of appeals and no sooner came to know about it, application for reference were filed and Tribunal was moved for stay. Additionally, levy of penalties u/s 13(5) of the Act for non-payment of the disputed demands has been challenged on the ground that the provisions of Section 13(5) are unconstitutional and ultra vires as no provision for grant of opportunity is provided there before such levy. It is stated that during pendency of appeals, Rs. 18,19, 790/- was paid and pursuant to direction given by this Court by order dated 26-3-1991, 50% of the balance dues amounting to Rs. 9,09,900/- has been paid, According to learned counsel for Revenue, petitioner's stand having not been accepted by three forums, it has to be held that there is no prima facie, case; balance of convenience is in favour of Revenue, and no material has been placed to show that petitioner would suffer irreparable loss if the disputed demand is paid. 4. We shall deal with first relating to validity of Section 13(5) of the Act. It is pleaded that it does not provide for grant of opportunity though levy of penalty involves civil consequences and therefore is unconstitutional. Though there is no specific provision in Section 13(5) of the Act for grant of an opportunity before levy of penalty, principles of natural justice obligate that before imposition of penalty an opportunity has to be granted. Where a statutory provision does not exclude natural justice, the requirement of affording an opportunity can be assumed, when the proceedings are quasi-judicial. Though there is no specific provision in Section 13(5) of the Act for grant of an opportunity before levy of penalty, principles of natural justice obligate that before imposition of penalty an opportunity has to be granted. Where a statutory provision does not exclude natural justice, the requirement of affording an opportunity can be assumed, when the proceedings are quasi-judicial. Even if a statute is silent and there are no positive words in the Act or Rules made there under spelling out the need to hear the party whose rights and interest are likely to be affected, the requirement to follow the fair procedure before taking a decision must be read to the statute unless the statute provides otherwise. The principles of natural justice must be read into unoccupied interstices of the statute unless there is a clear mandate to the contrary. No form or procedure should ever be permitted to exclude the presentation of a litigant's defence. Even in the absence of a provision in procedural laws, power inheres in every Tribunal, of a judicial or quasi-judicial character, to adopt modalities necessary to achieve requirements of natural justice and fair play. Procedure is grounded on principles of. natural justice. It has been a cherished principle. "The right of a man to be heard in his defence is the most elementary protection". (See Pullogh v. Abardon, 1971 (2) All ER 1273. Where the statute is silent about the observance of the principles of natural justice, such statutory silence is taken to imply compliance with the principles of natural justice. The application of natural justice becomes presumptive, it may be excluded by express words of statute or necessary intendment. (See Swedesi Cotton Mills etc v. Union of India etc. etc. AIR 1961 SC 818 Is aim is to secure justice or to prevent miscarriage of justice. Principles of natural justice do not supplant the law, but supplement it. These rules operate only in areas not covered by any law validly made. They are means to an end and not an end in themselves. Audi alteram pattern rule is a highly effective one designed to act as a healthy check on the abuse or misuse of power. Hence its reach should not be narrowed and its applicability circumscribed. lt has many facets. Two of them are notice of the case to be met and opportunity to explain. Audi alteram pattern rule is a highly effective one designed to act as a healthy check on the abuse or misuse of power. Hence its reach should not be narrowed and its applicability circumscribed. lt has many facets. Two of them are notice of the case to be met and opportunity to explain. This rule is universally respected and duty to afford a fair hearing in Lord Danning's off-quoted language is "a duty lying upon everyone who decides something" in the exercise of legal power. Wherever civil consequences are involved, invariably principles of natural justice are to be followed. Civil consequence undoubtedly covers infraction of not merely property or personal rights but of civil liberties, material deprivation and non-pecuniary damages. Fairness is a flexible pragmatic and relative concept, not a rigid, ritualistic or sophisticated abstraction, In the aforesaid premises, the irresistible conclusion is that opportunity has to be granted before imposition of penalty u/s 13(5) of the Act. Mere absence of a specific requirement to grant opportunity does not render the provision unconstitutional, since the deficiency is made good by principles of natural justice. 5 A bare look at the provision makes it clear that levy of penalty Is discretionary, and in a given case the dealer or person assessed to tax satisfying the concerned authority that it had sufficient cause for not making payment within due date, no penalty may be imposed The use of the word "may" throws sufficient light on the legislative intention ; in the context it is used The word has been used in the permissive sense and does not make it obligatory. The word has been, used in a penal statute. Every technical or unintended breach does not attract penalty. Some contumacy must exist. The very fact that maximum limit of penalty has been indicated, without indicating any minimum limit shows that in an appropriate case token penalty may be imposed. If the dealer or person assessed satisfies the concerned authority that imposition of penalty is not warranted on the circumstances, it may not impose any penalty on consideration of the explanation offered. What would constitute a sufficient cause for not paying the demanded tax would depend on facts and circumstances of each case, end no strait jacket formula can be provided for. 6. What would constitute a sufficient cause for not paying the demanded tax would depend on facts and circumstances of each case, end no strait jacket formula can be provided for. 6. Coming to the question whether petitioner had a sufficient cause for not paying the amount demanded within due time, it is seen that about 50% of the disputed amount had been paid during pendency of appeals, and petitioner had moved the Tribunal for references which have been accepted and the matter is now pending in this Court. It had moved the Tribunal for stay. The position relating to levy of tax on works contract of the time was in a fluid stage. Several complex questions were involved. The controversy has been settled recently by the apex Court in Gannon Gunkerley and Co. and Ors. v. State of Rajasthan and Ors. 55 STC 204. in the aforesaid premises, levy of penalty of Rs. 1,81,989/- u/s 13(5) of the Act cannot be maintained. It needs to be noticed here that originally the petitioner was assessed to extra demands of R3. 8.86,74/-. The assessments were assessed before this Court in writ application. The assessments were set aside and fresh assessments were directed. Higher tax rates were applied at the time of fresh assessments and that is how present demands were raised. 7. Pursuant to interim direction of this Court on 26-3-1991, 50% of the balance disputed demand has been paid. It cannot be said that petitioner has not established a case for stay. Tribunal has referred several questions to this Court being of the opinion that questions of law are involved Though it cannot be generalised that whenever Tribunal makes a reference, a prima facie case for stay is established, yet in view of the complex nature of dispute involved, we are of the view that a case for grant of stay has been made out. When a reference is made, it is one of the factors on the question of stay. 8. Considering these aspects, we direct stay of realisation of balance amount involved for the aforesaid assessment periods and years till disposal of the references by this Court. The writ applications are allowed to the extent indicated above. P.C. Naik, J. 9. I agree.