( 1 ) THIS judgment will dispose of four Letters Patent Appeals and fifteen writ petitions. All these raise common questions relating to the validity of the levy of tax by the Municipal Corporation of Delhi (M. C. D.) payable by the consumers of electricity on energy generated by themselves within the area of the M. C. D. The petitioners, the Delhi Cloth and General Mills Company Ltd. and another earlier filed two writ petitions in this Court challenging such a levy. These were decided by a learned Single Judge by his judgment dated 28 September 1979 [i. L. R. 1981 (2) Delhi 8461 which is impugned. He partly allowed the petitions. M. C. D. had fixed the tax payable ion the consumption, sale and supply of electricity at the rate of 3 paise per KWHR by the consumers of electricity on engergy obtained from the M. C. D. , the licensee and fixed 5 paise per KWHR payable by consumers of electricity on energy generated by themselves. The resolution fixing the rates also specified the date from which the tax would be payable. The learned Single Judge while upholding the validity of the levy held that the classification of more taxation on the consumers of self generated el