B.P. Jeevan Reddy, CJ.

1. This is a petition for issuance of a writ in the nature of prohibition restraining the respondents (assessing authorities under the Income-tax Act) from proceeding with, or passing any orders in, the assessment proceedings against the petitioner relating to the assessment year 1971-72.

2. The petitioner is a company registered under the, Companies Act. It is engaged in the business of generation and supply of power. It is an assessee under the Income-tax Act. For the assessment year 1971-72, the petitioner filed a return of its income, on the basis of which an order of assessment was made by the Income-tax Officer on February 27, 1975, under Section 142 of the Act. It was a case of nil assessment. Subsequently, the Income-tax Officer sought to reopen the assessment by issuing a notice under Section 148, which was questioned by the petitioner by way of a writ petition in this court (C.M.W.P. No. 578 of 1976). This aspect is not really relevant for our purpose and it is also not clear as to what happened to the said writ petition. What is, however, relevant is that by a notice dated February 7, 1977, the Commissioner of Income-tax proposed to revise