6(1)At any time when a suspension order is in operation the planning authority may by order direct—S
(a)that steps for the protection of the environment shall be taken in addition to or in substitution for any of the steps which the suspension order or a previous order under this sub-paragraph specified as required to be taken, or
(b)that the suspension order or any order under this sub-paragraph shall cease to have effect.
(2)An order under sub-paragraph (1) is in this Act referred to as a “supplementary suspension order”.