1. These appeals are directed against the judgment and order dated 17.2.89 of the Kerala High Court in O.P. No. 10002 of 1983, whereby the High Court has held, that the concessional rates for supply of electricity incorporated in special agreement under S.49(3) of the Electricity Supply Act, 1948 (hereinafter referred to as the 'Act') entered into between the Indian Aluminium Co. Ltd. (hereinafter referred to as the 'company') and the Kerala State Electricity Board (hereinafter referred to as the 'Board') was validly rescinded by the statutory amendment incorporating sub-s.(5) in S.49 of the Act by the Act No. 7 of 1983. The High Court has further found that the demand of duty at the rate specified under Kerala Electricity Duty Act which was in excess of concessional duty was invalid. Consequently, the said demand of duty was quashed. It is in this way the State of Kerala is in appeal against the quashing of demand of duty, whereas the company has come up to this Court against that part of the judgment whereby the High Court has upheld the validity of sub-s.(5) of S.49 of the Act. The State of Kerala after the judgment under appeal was delivered filed a review petition