The Government has the power to prescribe different tariff rates for different industries under Section 4 of the Tamil Nadu Revision of Tariff Rates on Supply of Electrical Energy Act, 1979 (Act 1 of 1979), and the guidelines for revising the tariff rates under Section 4 of the Act are sufficient.

KANAKARAJ, J.

These writ appeals and the writ petitions relate to a common question as to whether the appellants and the writ petitioners are entitled to claim certain concessional electricity tariff rate applicable to certain power intensive factories and units and for that purpose they seek to quash certain Government orders denying such concessions issued under the Tamil Nadu Revision of Tariff Rates on Supply of Electrical Energy Act, 1979 (Act 1 of 1979) (hereinafter referred to as Act (1 of 1979). To appreciate the grounds on which the relief is sought for, it is essential that we should know the facts of the case.

2. The appellants in W.A, Nos. 2 to 10 of 1988 were the writ petitioners in W. P. Nos. 2211 of 1987, 1146 of 1982, 4948 of 1985, 5426 of 1982, 5427 of 1982, 5428 of 1982, 1147 of 1982, 4949 of 1985 and 7186 of 1985 respectively. They are engaged in the production of rough synthetic gems which are subsequently cut and polished by skilled manual labour into synthetic gems of various colours, shapes and sizes used for personal ornaments in gold, silver etc. and also for certain industrial uses. We do not propose to set out the prayer in each of the writ petitions at this stage and we will refer to the prayer after setting out the history relating to the imposition of electricity tariff rate in the State of Tamil Nadu. The Electricity (Supply) Act, , 1948 contained provision namely, Section 49 of the Act enabling the Board to supply electricity to any person not being a licensee upon such terms and conditions as the Board thinks fit. Sub-section (2) of Section 49 of the Act enjoins the Board to have regard to all or any of the factors set out therein. Sub-section (3) of Section 49 enables the Board to fix different tariff rates for the supply of electricity to any person not being a licensee having regard to the geographical situation, the nature of the supply and purpose for which supply is required and other relevant factors. Sub-section (4) of Section 49 imposes a duty on the Board not to show undue preference to any person. We have referred to the above provisions of law only for purpose of appreciating the arguments and for the purpose of cautioning ourselves that the impugned Government Orders and the action of the Board were not under the said provisions of law, but had been passed under the said Act l of 1979. It transpires that prior to exercise of the power of the Government under Act 1 of 1979, the Government was exercising the powers under the Tamil Nadu Essential Articles Control and Requisitioning Act, 1949 which defined essential article as including electrical energy. After the Act 1 of 1979 came to be enacted the Government has been fixing the tariff rates payable to the Tamil Nadu Electricty Board by any consumer on the electrical energy supplied by the Board in accordance with Section 3 of the Act and as specified in the Schedule to the Act. Act 1 of 1979 itself contained the Schedule to the Act prescribing the tariff rates applicable with effect from 1-3-1978. Section 4 of the Act 1 of 1979 enabled the State Government after taking into account the cost of production of energy and such other matters as may be prescribed, by notification, to amend the provisions of the Schedule to the Act. It is not disputed "the other matters" mentioned above was never prescribed by the State Government. But they had been amending the Schedule from time to time by exercising the said power and issuing various Government orders.

3. The appellants in W.A. Nos. 2 to 10 of 1988 had entered into an agreement with the State Electricity Board on 15-4-1968 in relation to the supply of electrical energy in bulk at its factory at Chikkadasampalayam, Avanasi Taluk. The tariff rates and the minimum guarantees are prescribed in the agreement itself. There was, of course, a clause which says that the tariff rates are subject to revision that may be decided on by the Board from time to time. It is not disputed that t