(1) Where a company makes a distribution which is a relevant distribution for the purposes of section 147, including part of a distribution treated under section 147(4) as a relevant distribution, and which is in respect of any right or obligation to which section 139 applies, the company shall make a supplementary distribution of an amount equal to the excess of the amount of the tax credit which would have applied in respect of the relevant distribution, if section 147(5) had not been enacted, over the amount of the tax credit which in accordance with section 147(5) applies to the relevant distribution.
(2) Where the whole or part of a supplementary distribution under subsection (1) which is a relevant distribution for the purposes of section 147 is received by a company in an accounting period, then, for the purposes of that section -
(a) the whole or part, as the case may be, of the supplementary distribution shall be an amount taken into account under the definition of "E", a