If in pursuance of F1section 426 of the Taxes Act 1988 (consequences for income tax of apportionment of income etc. of close company) a person is assessed to income tax, then, in the computation under Chapter II of Part II of this Act of the gain accruing on a disposal by him of any shares forming part of his interest in the company to which the relevant apportionment relates, the amount of the income tax paid by him, so far as attributable to those shares, shall be allowable as a deduction.

Subsection (1) above shall not apply in relation to tax charged in respect of undistributed income which has, before the disposal, been subsequently distributed and is then exempt from tax by virtue of F1section 427(4) of the Taxes Act 1988 or in relation to tax treated as having been paid by virtue of F1section 426(2)(b) of that Act.

For the purposes of this section the income assessed to tax shall be the highest part of the individual’s income for the year of assessment in question, but so that if the highest part of the said income is taken into account under this section in relation to an assessment to tax the next highest part shall be taken into account in relation to any other relevant assessment, and so on.

For the purpose of identifying shares forming part of an interest in a company with shares subsequently disposed of which are of the same class, shares bought at an earlier time shall be deemed to have been disposed of before shares bought at a later time.

The provisions of this section shall be construed as if this section F2were included in sections 426 to 428 of the Taxes Act 1988.