If it appears to the Secretary of State, after consultation with the local planning authority, to be expedient that any order to which this subsection applies should be made, he may give directions to the local planning authority requiring them to submit to him such an order for his confirmation, or may himself make such an order; and any order so made by the Secretary of State shall have the like effect as if it had been made by the local planning authority and confirmed by the Secretary of State under Part III or IV of this Act.
Subsection (1) of this section applies to the following orders, that is to say—
(a) orders under section 45 of this Act, or under the provisions of that section as applied by any order or regulations made under Part IV of this Act;
(b) orders under section 51 of this Act;
(c) tree preservation orders and orders amending or revoking them.
The provisions of Part III or Part IV of this Act, and of any regulations made thereunder, with respect to the procedure to be followed in connection with the submission by the local planning authority of any order to which subsection (1) of this section applies, with respect to the confirmation of such an order by the Secretary of State, and with respect to the service of copies thereof as so confirmed, shall have effect, subject to any necessary modifications, in relation to any proposal by the Secretary of State to make such an order by virtue of subsection (1) of this section, in relation to the making thereof by the Secretary of State, and in relation to the service of copies thereof as so made.
Without prejudice to subsection (3) of this section, where the Secretary of State proposes under subsection (1) of this section to make any such order as is mentioned in subsection (2)(a) or (b) of this section he shall serve a notice of the proposal on the local planning authority; and if within such period as may be specified in the notice (not being less than twenty-eight days from the date of service) the authority so require, the Secretary of State before making the order shall afford to the authority an opportunity of appearing before, and being heard by, a person appointed by him for the purpose.
If the Secretary of State is satisfied, after holding a local inquiry—
(a) that the council of a county, county borough, London borough or county district have failed to take steps for the acquisition of any land which, in the opinion of the Secretary of State, ought to be acquired by that council under section 112 of this Act for a purpose which it is necessary to achieve in the interests of the proper planning of an area in which the land is situated; or
(b) that a local authority have failed to carry out, on land acquired by them under section 68 of the Act of 1962 or section 112 of this Act or appropriated by them under section 121 of this Act, any development which, in the opinion of the Secretary of State, ought to be carried out,
the Secretary of State may by order require the council or authority to take such steps as may be specified in the order for acquiring the land, or carrying out the development, as the case may be.
Any order under subsection (6) of this section shall be enforceable, on the application of the Secretary of State, by mandamus.