A taxpayer has a right to appeal an order that is prejudicial to him. Alternatively he can make application to Principal CCIT/CIT or CCIT/CIT u/s 264 to seek relief having not preferred an appeal against any such order.
However the power held in section 264 is mere discretionary. Secondly there is no appeal either against any order passed u/264.
It is this scenario that the Calcutta High Court in  444 ITR 227 (Cal) citing the provisions under Explanation 1 below section 264(7) refused to entertain the writ petition.
The cited explanation says that any order of the Commissioner under section 264 of the Act declining to interfere will be deemed not to be an order prejudicial to the assessee.