70. Avoidance of tax.

Notwithstanding any other provision of the Tax Acts or the Capital Gains Tax Acts, sections 65, 66, 67, 68 and 69 shall not have effect as respects a transfer or disposal (as the case may be) unless it is shown that the transfer or disposal is effected for bona fide commercial reasons and does not form part of any arrangement or scheme of which the main purpose, or one of the main purposes, is avoidance of liability to income tax, corporation tax or capital gains tax.