15.—(1) Section 112(1)(b) of the Act has effect in relation to each local authority subject to the provisions of paragraph (2).
(2) Until the expiry of the period of 8 years beginning with the day on which the first regulations made by the local authority in question under section 115(1) of the Act come into force, the duty imposed by section 112(1)(b) of the Act does not have effect in relation to that authority.