A claim for group relief by a company as a member of a consortium shall require the consent of each other member of the consortium, notified to the inspector in such form as the Board may require, in addition to the consent of the surrendering company.

If the inspector discovers that any group relief which has been given is or has become excessive he may make an assessment to corporation tax under Case VI of Schedule D in the amount which ought in his opinion to be charged.

Subsection (3) above is without prejudice to the making of an assessment under section 29(3)(c) of the Taxes Management Act 1970, and to the making of all such other adjustments by way of discharge or repayment of tax or otherwise as may be required where a claimant company has obtained too much relief, or a surrendering company has forgone relief in respect of a corresponding amount.