Jawahar Lal Gupta, J.

1. Is the provision of Section 2MB, Explanation 1, as amended by the Finance Act, 2001, ultra vires ? This is the short question that arises for consideration in this case.

2. The original provision was in the following terms :

"Explanation I--In this section, assessed tax means,-- (a) for the purposes of computing the interest payable under Section 140A, the tax on the total income as declared in the return referred to in that section;

(b) in any other case, the tax on the total income determined under Sub-section (1) of Section 143 or on regular assessment, as reduced by the amount of tax deducted or collected at source in accordance with the provisions of Chapter XVII on any income which is subject to such deduction or collection and which is taken into account in computing such total income."

3. By the Finance Act, 2001, the above provision stands substituted by the following provision with effect from April 1, 1989 :

"Explanation 1. --In this section, assessed tax means the tax on the total income determined under Sub-section (1) of Section 143 or on regular assessment as reduced by the amount of tax deducted or collected at source in accordance w