(1)Where, by virtue of any of the preceding provisions of this Part of this Act, any survey is required to be carried out, or any structure or local plan or proposals for the alteration, repeal or replacement thereof are required to be prepared or submitted to the Secretary of State, or steps are required to be taken for the adoption of any such plan or proposals, then—
(a)if at any time the Secretary of State is satisfied, after holding a local inquiry or other hearing, that the local planning authority are not carrying out the survey or are not taking the steps necessary to enable them to submit or adopt such a plan or proposals within a reasonable period; or
(b)in a case where a period is specified for the submission or adoption of any such plan or proposals, if no such plan or proposals have been submitted or adopted within that period,
the Secretary of State may carry out the survey or prepare and make a structure plan or local plan or, as the case may be, alter repeal or replace it, as he thinks fit.
(2)Where under subsection (1) of this section the Secretary of State has power to do anything which should have been done by a local planning authority, he may, if he thinks fit, authorise any other local planning authority who appear to the Secretary of State to have an interest in the proper planning of the district of the first-mentioned authority to do that thing.
(3)Where under this section anything which ought to have been done by a local planning authority is done by the Secretary of State or another such authority, the preceding provisions of this Part of this Act shall, so far as applicable, apply with any necessary modifications in relation to the doing of that thing by the Secretary of State and the latter authority and the thing so done.
(4)Where the Secretary of State incurs expenses under this section in connection with the doing of anything which should have been done by a local planning authority, so much of those expenses as may be certified by the Secretary of State to have been incurred in the performance of functions of that authority shall on demand be repaid by that authority to the Secretary of State.
(5)Where under this section anything which should have been done by one local planning authority is done by another such authority, any expenses reasonably incurred in connection with the doing of that thing by the latter authority, as certified by the Secretary of State, shall be repaid to the latter authority by the former authority.