GOPALAN NAMBIYAR C.J. :- These Writ Appeals raise the same question in regard to the validity of the revision of tariffs effected by the Kerala State Electricity Board. By way of example, it would be enough to refer to the facts in W. A. No. 466 of 1976. The facts in the remaining cases are, it was admitted, practically the same, and need not be repeated.

W. A. No. 466 of 1976

The appellant in this Writ Appeal is the Travancore-Cochin Chemicals Limited, Eloor. Udyogamandal. The agreement executed by it with the Electricity Board is Ext. P2 dated 26-3-1974. Clause 9 of the agreement is as follows :

"9. The cosumer shall pay for all electrical energy supplied to him by the Board and ascertained as hereinbefore provided an amount calculated at the rate and in accordance with the terms given in the Schedule.

The rates, shown in the Schedule, are liable to revision by the Board from time to time in which case the revised rate/rates shall be binding on the consumer and the levy of charges for electricity consumed shall be at the revised rate or rates."

By cl. 12, the agreement was to be in force for a period of 10 years from 25-11-1970, which was the date on which the previous agree