JUDGMENT

S.B. MAJMUDAR, J.

(1) LEAVE granted in Special Leave Petition (C) No. 5355 of 1991.

(2) IN this group of appeals identical grievance is made by the appellants who are consumers of electricity supplied by the respondent U.P. State Electricity Board ("the Board" in short). Their grievance is that though by notifications dated 29/10/1982, 13/7/1984 and 28/1/1986 the respondent- Board in exercise of its powers under Section 49 of the Electricity (Supply) Act, 1948 (hereinafter referred to as "the Act") had held out a promise to new industrialists seeking to establish industries in different parts of the State of Uttar Pradesh, that on the charges of electricity consumed by them they will be given 10 rebate for a period of three years from the date of commencement of supply of electricity to them for the first time, the respondent-Board had arbitrarily and prematurely withdrawn concession of the said rebate by a latter notification dated 31/7/1986 which is impugned in these proceedings. Various writ petitions were filed in the High court of Judicature at Allahabad challenging the said impugned notification. They were heard together by a division bench consisting of B.P. Jeevan Reddy, C.J. (as he then was) and V.N. Mehrotra, J. Diverse contentions were canvassed in support of the writ petitions. In the forefront it was submitted that the Board was bound on the principle of promissory estoppel to continue the dEVELOPMENT rebate to these new industries for a period of three years as indicated in the earlier notifications and consequently the Board could not have arbitrarily withdrawn the said dEVELOPMENT rebate prior to the expiry of three years period available to the industries concerned under these earlier notifications. It was also contended that in any case the impugned notification applied prospectively and could not have any retrospective effect on earlier existing new industries.

(3) THE respondent-Board on the other hand opposed these contentions and submitted that all the writ petitioners-consumers had entered into contracts by way of written agreements with the Board before taking electricity supply at their premises and as per the terms of the said agreements they had already subjected themselves to all future actions of the Board by which the electricity tariff could be revised by the Board at any time and that would include even the dEVELOPMENT rebate which could be withdrawn at any time at the Boards discretion as agreed to by all of them. The division bench of the High court in the impugned judgment speaking through B.P. Jeevan Reddy, C.J., framed three common issues covering these controversies between the parties as under:

"(A) Whether the Board is estopped from withdrawing the said rebate before the completion of the 3/5 year period, by virtue of the doctrine of promissory estoppel?

(B) Whether the agreement executed by the petitioners bars them from questioning the impugned notification?

(C) Whether the impugned notification has no application to existing consumers and does it apply to only those consumers who receive the supply on or after 1/8/1986?"

After hearing the contesting parties through their advocates the High court on the first point came to the conclusion that the respondent-Board was estopped by virtue of the doctrine of promissory estoppel from withdrawing the dEVELOPMENT rebate before the completion of the period of three years. However on the second point the court came to the conclusion that the writ petitioners were barred from questioning the impugned notification on the express terminology found in the agreements entered into by them with the Board for supply of electricity and under those agreements the Board was given full play to revise the tariff rates which included dEVELOPMENT rebate also from time to time and consequently the impugned notification was not illegal. On the third issue it was held that the notification dated 31/7/1986 cou