The Secretary of State may approve any proposals submitted to him under section 11(5)(a) with or without modifications.
The Secretary of State may at any time give to the Executive—
(a) such directions as he thinks fit with respect to its functions, or
(b) such directions as appear to him requisite or expedient to give in the interests of the safety of the State.
The Secretary of State may not under subsection (2) give any directions with regard to the enforcement of the relevant statutory provisions ... in any particular case.
The reference to directions in subsection (2)(a)—
(a) includes directions modifying the Executive's functions, but
(b) does not include directions conferring functions on the Executive other than any functions of which it was deprived by previous directions given under subsection (2)(a).