Income and Corporation Taxes Act 1988

5 A provision of paragraph 3 or 4 above requiring tax to be calculated as if an amount were treated as the highest part of the claimant’s total income shall apply notwithstanding any provision of the Income Tax Acts directing other income to be treated as the highest part of his total income, but for the purposes of those paragraphs his total income shall be deemed—

(a) not to include any amount in respect of which he is chargeable to tax under section 148, and

(b) to include, in respect of any amount which would otherwise be included therein by virtue of section 547(1)(a), no greater amount than the appropriate fraction thereof within the meaning of section 550.