by taking a specific stand as they had done earlier in the case of wired glass. The appellants, however, questioned the validity of the levy only on February 20, 1976 on the ground that tariff Item 23A (1) of the First Schedule to the Act under which the duty has been levied was not applicable to the goods. While the Department refused to accept the said plea, the High Court has upheld it. In view of the decision of the High Court, the fact that the appellant had paid duty in excess of what they were bound in law to pay should be now taken as having been established. It is not disputed that if the appellants had filed a suit within the period of limitation the excess amount would have become refundable by virtue of Section 72 of the Indian Contract Act. Section 17(1)(c) of - the Limitation Act, 1963 provides that where in the case of any suit or application for which a period of limitation is prescribed under that Act, the suit or application is for relief from the consequence of a mistake, the period of limitation shall not begin to run until the plaintiff or applicant had discovered it or could have with reasonable diligence discovered it. In the instant case the date on which the mistake was discovered by the appellants or the date on which the appellants could with reasonable diligence have discovered it is not clear from the record before us. No efforts also was made in the course of the arguments urged on behalf of the appellants to establish it. We have, therefore, to assume that on the date each payment of excise duty made by the appellants in excess of the proper duty payable by them, the appellants could have discovered with due diligence that the duty claimed from them was excessive. Under Article 113 of the Limitation Act, 1963 which is applicable to this case, a suit for recovery of such excess duty had to be filed within three years from the date of payment to the Department. But the appellants instead of filing a suit, first filed a writ petition in Special Civil Application No. 1365 of 1976 on September 28, 1976 and that petition had to be withdrawn in view of clause (3) of Article 226 the Constitution as it stood then because the alternative remedy by way of an appeal was available. The appellants could, therefore, file the writ petition out of which the appeal arises only after the disposal of the revision petition by the Government of India as mentioned earlier. lt is not disputed that the High Courts have power, for the purpose of enforcement of fundamental rights and statutory rights, to make consequential orders for repayment of money realised by the Government without the authority of law under Article 226 of the Constitution. This is an alternative remedy provided by the Constitution in additional to but not in supersession of the ordinary remedy by way of suit in the absence of any provision which would bar such a suit either expressly or by necessary implication. While there are different periods of limitation prescribed for the institution of different kinds of suits by the limitation Act, 1963, there is no such period prescribed by law in respect of petitions filed under Article 226 of the Constitution. Whether relief should be granted to a petitioner under Article 226 of the Constitution where the cause of action had arisen in the remote past is a matter of sound judicial discretion governed by the doctrine of laches. Where a petitioner who could have availed of the alternative remedy by way of suit approaches the High Court under Article 226 of the Constitution, it is appropriate ordinarily to construe that any unexplained delay in the filing of the writ petition after the expiry of the period of limitation prescribed for filing a suit as unreasonable. This rule,