(1)The Secretary of State may by order made with the consent of the Treasury vary either or both of the percentages mentioned in section 516 (contributions by Secretary of State to expense of making grants).
(2)An order—
(a)may make different provision with respect to different cases or descriptions of case, including different provision for different areas, and
(b)shall be made by statutory instrument and shall not be made unless a draft of it has been laid before and approved by resolution of the House of Commons.
(3)An order has effect with respect to applications for grants approved after such date as may be specified in the order, and the specified date shall not be earlier than the date of the laying of the draft.