The inclusion of demurrage charges and transmission and distribution losses in the computation of fuel adjustment charges was not arbitrary and violative of Article 14 of the Constitution. The levy of fuel adjustment charges on LIP consumers alone was not arbitrary or discriminatory as there were valid considerations to fix differential rates for various categories of consumers. The limitation period for recovery of dues under the Tariff began from the date when the accounts were settled and not from the date when the fuel adjustment charges became due.

( 1 ) THE petitioners in this batch of writ petitions have assailed certain provisions of the electricity Tariff issued from time to time by the Municipal Corporation of Delhi as discriminatory and have questioned the computation of the rate of fuel adjustment charges on the basis of actual cost of fuel used.

( 2 ) THE Municipal Corporation of Delhi is a body corporate established under S. 3 of the Delhi Municipal Corporation Act, 1957 (hereinafter called the Act ) and is charged with the Municipal Government of Delhi under its statutory provisions. Under S. 42 of the Act, one of the obligatory functions of the Municipal Corporation of Delhi (for short, called the corporation ) is the construction or purchase, maintenance, extension, management and conduct of any undertaking for the generation or supply and distribution of electricity to the public. For the efficient performance of its functions, a number of municipal authorities under the Corporation are constituted including the Delhi Electric Supply Committee (for short called the D. E. S. C. ). The D. E. S. C. is responsible for the conduct and management of the Delhi Electric Supply Undertaking (for short called DESU) and for the efficient discharge of such responsibility is to exercise such powers and perform such functions as are conferred or imposed by or under the Act. The provisions relating to the electric supply are contained in Chap. XIII, Ss. 274 to 286 of the Act. In addition to the provisions of the Act, the provisions of the Indian Electricity Act, 1910, the Indian Electricity Rules, 1956 framed thereunder and the Electric (Supply) Act, 1948 are relevant. Section 275 lays down the duty of the D. E. S. C. to develop and maintain an efficient, coordinated and economical system of electric supply for the whole of the Union Territory of Delhi and for that purpose to take a number of specified steps from time to time. In the discharge of its functions in relation to electric supply, the D. ES. C. , inter alia, is to promote the use of all economical methods of generating, transmitting and distributing electricity. By virtue of S. 277, the Corporation is to have all the powers and obligations of a licensee under the Indian Electricity Act, 1910. According to sub-sec. (2) of S. 278 the General Manager (Electricity) is authorised on behalf of the Corporation to exercise all powers and be subject to all the obligations of a licensee under the Indian Electricity Act, 1910 or any other law for the time being in force relating to the generation or supply of electricity. Section 281 contains the powers of the Corporation to make arrangements with licensees and for that purpose enter into agreements with them without showing any undue preference to any licensee. Section 283 makes provisions for the charges for the supply of electricity and reads as under :

"subject to the provisions of any law for the time being in force, charges shall be leviable for the supply of electricity by the Corporation at such rates as may, from time to time, be fixed by the Delhi Electric Supply Committee with the approval of the Corporation. "in Exercise of the powers conferred by S. 283 of the Act, charges for supply of electricity, called electricity Tariff, are fixed from time to time almost yearly. The Tariff, divides the consumers for the purposes of charging them in different categories like domestic, non- domestic, industrial load, agriculture, street lighting, night load tariff, railway traction, temporary supply etc. It also includes general conditions of application, one of which is that the supply of electricity in all cases is subject to the execution of agreements including compliance of commercial formalities by the consumers. The industrial consumers are further sub-divided into small industrial power consumers and large industrial power consumers. We are concerned in these cases with the bulk consumers called Large Industrial Power (LIP) consumers.

( 3 ) ON February