Where by virtue of paragraph 3 of Schedule 9 to this Act a parking place has been designated under section 45 of this Act by the Secretary of State—
(a)he may make grants out of moneys provided by Parliament towards the cost of the provision and maintenance of off-street parking places whether in the open or under cover, or for any purpose such as is mentioned in section 55(4)(d)(i) or (ii) of this Act; but
(b)in exercising his powers under this section he shall use his best endeavours to secure that the aggregate of the amounts paid by him by way of grants does not exceed the difference between—
(i)the aggregate of the sums received by him by way of charges made by him for vehicles left in parking places designated by him under section 45 of this Act; and
(ii)the aggregate of the expenses incurred by him in the provision, operation and maintenance of the parking places in respect of which those charges are made.