6SSubject to paragraph 7, on the adoption or approval of a local plan under section 17 or 19 so much of any old development plan as relates to the area to which the local plan relates shall cease to have effect.
7SThe Secretary of State may by order direct that any of the provisions of the old development plan shall continue in force in relation to the area to which the local plan relates and, if he does so, the provisions of the old development plan specified in the order shall continue in force to the extent so specified.
8SThe Secretary of State may by order wholly or partly revoke a development plan continued in force under this Schedule whether in its application to the whole of the district of a planning authority or in its application to part of that district and make such consequential amendments to the plan as appear to him to be necessary or expedient.
9SBefore making an order with respect to a development plan under paragraph 7 or 8, the Secretary of State shall consult the planning authority for the district to which the plan relates.