s 50 Alteration of simplified planning zone schemes .
(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2) A planning authority may at any time decide― (b) to alter a simplified planning zone scheme adopted by them, or (c) with the consent of the Secretary of State, to alter a scheme approved by him. (3) Schedule 5 has effect with respect to the ... alteration of simplified planning zone schemes and other related matters.