JUDGMENT

PATHAK, CJI.:— These appeals by special leave are directed against the judgment and order of the High Court of Delhi dismissing writ petitions complaining of discriminatory treatment between the appellants and the State Trading Corporation in regard to the rate of customs duty levied on the import of edible oils. A number of writ petitions have also been filed directly in this Court by other private importers based on the same complaint. They pray for relief in terms of the same rate of customs duty as has been applied to the import of edible oils effected by the State Trading Corporation.

2. As common question of law arises in these appeals and writ petitions and the facts are substantially similar, we propose to treat Writ Petition No. 3800 of 1980, M/s. Liberty Oil Mills v. Union of India & others, as the leading case.

3. On 17 January, 1977 the Government of India issued a Public Notice permitting private parties to import edible-oils for direct human consumption. It was not permissible to use such imported oils for the manufacture of Vanaspati Or for any industrial purpose. Under the Import Policy of 1978-79, the Government canalised the import of edible oils so that the State Trading Corporation alone was permitted to import edible oils. Some of the private importers who had entered into firm commitments with foreign suppliers and were now being denied permission to import the edible oils filed writ petitions in various High Courts, and these writ petitions were allowed and they were granted licences to import the edible oils.

4. Prior to 1 March. 1979 the import of edible oils was exempt from customs duty, but with effect from that date the exemption was partially withdrawn and certain specified oils were made liable to import duty at 121/2 per cent. Exemption was granted from additional duty chargeable under S. 3 of the Customs Tariff Act, 1975. Auxiliary duty chargeable under the Finance Act was, however, payable. On 17 March, 1979 the Government passed an order of exemption in favour of the State Trading Corporation under S. 25(2) of the Customs Act, 1962 whereby the imports of the specified oils by the State Trading Corporation were made liable to customs duty at 5 per cent only, and there was a total exemption from auxiliary and additional duty. The imports of the same specified oils by private importers were made liable to customs duty at 12.5 per cent ad valorem. The concessional rate of customs duty in favour of the State Trading Corporation was restricted to imports aggregating 3 lakh tonnes initially. That quantity was enlarged to 6 lakh tonnes on 26 June, 1979. On 31 October, 1979, a further order of exemption was made in favour of the State Trading Corporation granting it exemption for imports of five lakh tonnes of the specified oils, and this was followed on 31 March, 1981 by another order of exemption in respect of an aggregate quantity of 5 lakh tonnes of oil. It may be mentioned that on 12 May, 1981 the import of edible oil was exempted from the levy of auxiliary duty.

5. On 18 July, 1981, the Government reduced the exemption granted to the import of the specified oils by private operators by raising the customs duty to 421/2 per cent. The exemption in favour of the State Trading Corporation continued without change. Thereafter on 26 July, 1981, by Ordinance No. 9 of 1981 the government raised the tariff rate of customs duty to 200 per cent ad valorem by amending the Customs Tariff Act, 1975. At the same time exemption was granted insofar that the effective rate of duty on the import of the specified edible oils, except Rape Seed oil and Soyabean oil, was fixed at 125 per cent. The exemption from auxiliary duty was withdrawn. In the result a private importer had to pay a basic duty of 125 per cent and auxiliary duty of 25 per cent on the import of edible oils. The oil seeds imported by the State Trading Corporation continued to attract customs duty at 5 per cent.

6. Writ petitions were filed in the