Exercise of powers to be subject to sanction by Corporation of the necessary expenditure.

The exercise by any municipal authority of any power conferred or the performance of any duty imposed by or under this Act which will involve expenditure shall, except in any case specified in sub-section (2) of section 86 or in sub-section (2) of section 355, be subject to the conditions that— (a) such expenditure, so far as it is to be incurred in the official year in which such powers exercised or duty performed, is provided for under a current budget-grant; and (b) if the exercise of such power or the performance of such duty involves or is likely to involve expenditure for any period or at any time after the close of the said official year, the sanction of the Corporation is taken before liability for such expenditure is incurred. CHAPTER VII. Contracts.