NAGENDRA PRASAD SINGH, J.

1. The petitioners in these writ applications have questioned the authority of the respondent-Bihar State Electricity Board to issue bills in respect of fuel surcharge at an enhanced rate for the financial years 1979-80 and 1980-81.

2. The petitioners Companies have factories in the different parts of the State of Bihar for which they have entered into agreements with the Bihar State Electricity Board (hereinafter to be referred to as the Board) for supply of high tension line. From time to time notifications relating to tariff have been issued by the respondent-Board in the exercise of powers conferred on them by Ss.46 and 49 of the Electricity (Supply) Act, 1948 (hereinafter to be referred to as the Act). The last tariff, which is in force, was issued on 1-4-1979 setting out the details of the charges which a consumer of the electric energy has to pay. The petitioners are required to pay fuel surcharge as well. In the year 1979 fuel surcharge at a provisional rate of 1 paise per unit was levied which was subsequently increased to 3 paise per unit. However, in the final bill submitted for the financial year 1979-80 it was raised from 3 paise per u