An Executive shall so perform their functions as to ensure so far as practicable that the combined revenues of the Executive and any subsidiaries of theirs for any accounting period are not less than sufficient to meet their combined charges properly chargeable to revenue account in that period.

If in the case of any accounting period it is not practicable for an Executive to ensure that those revenues are sufficient to meet those charges, subsection (1) above shall have effect in relation to the next following accounting period as if the combined charges there referred to included an amount equal to the amount of the deficit.

For the purposes of this section there shall be disregarded any deficit or potential deficit in an accounting period to the extent to which it is or is to be covered by the appropriation of any reserves of the Executive available for the purpose if the appropriation of those reserves for that purpose has been proposed by the Executive in a plan prepared by them under section 3 below and approved by the Authority under section 4 below.

An Authority in exercising or performing any of their functions under this Part of this Act, under Part II of the Act of 1968 or under the Act of 1969 shall have regard to the duty imposed on an Executive by this section.

In this section " subsidiary " has the meaning given by section 92(1) of the [1962 c. 46.] Transport Act 1962, and the provisions of section 51(5) of the Act of 1968 (joint subsidiaries) so far as applying to the London Transport Executive shall accordingly be disregarded.