(1)Subject to subsection (2), the provisions of this Chapter shall come into force in the area of any local planning authority in Greater London or a metropolitan county (other than any area in that county which is part of a National Park) on such day as may be appointed in relation to that area by an order made by the Secretary of State.
(2)Subsection (1) does not apply in any area in relation to which an order has been made before the commencement of this Act under section 4(1) of the [1985 c. 51.] Local Government Act 1985 (commencement of Part I of Schedule 1 to that Act) and in any such area the provisions of this Chapter shall come into force at the commencement of this Act or, if later, on the day appointed by the order.
(3)Until a unitary development plan becomes operative under this Chapter for such an area as is mentioned in subsection (1) (or where parts of such a plan become operative on different dates until every part has become operative)—
(a)if it is the area of a local planning authority in a metropolitan county, Part I of Schedule 2 (which provides for existing plans to continue in force and applies some of the provisions of Chapter II) shall apply in relation to it;
(b)if it is the area of a local planning authority in Greater London, Part II of that Schedule (which makes similar provision) shall apply in relation to it; and
(c)Part III of that Schedule shall apply in relation to it for the purpose of making continuing provision for the transitional matters for which provision was made immediately before the commencement of this Act by Schedule 7 to the 1971 Act (old development plans etc.).
(4)The power to make orders under this section may be exercised so as to make different provision for different cases, including different provision for different areas.