(1)The Secretary of State may constitute a Planning Inquiry Commission to inquire into and report on any matter referred to them under subsection (2) in the circumstances mentioned in subsection (3).
(2)The matters that may be referred to a Planning Inquiry Commission are—
(a)an application for planning permission which the Secretary of State has under section 46 directed to be referred to him instead of being dealt with by a planning authority;
(b)an appeal under section 47 (including that section as applied by or under any other provision of this Act);
(c)a proposal that a government department should give a direction under section 57(1) that planning permission shall be deemed to be granted for development by a local authority or by statutory undertakers which is required by any enactment to be authorised by that department;
(d)a proposal that development should be carried out by or on behalf of a government department.
(3)Any of those matters may be referred to a Planning Inquiry Commission under this section if it appears expedient to the responsible Minister or Ministers that the question whether the proposed development should be permitted to be carried out should be the subject of a special inquiry on either or both of the following grounds—
(a)that there are considerations of national or regional importance which are relevant to the determination of that question and require evaluation, but a proper evaluation of them cannot be made unless there is a special inquiry for the purpose;
(b)that the technical or scientific aspects of the proposed development are of so unfamiliar a character as to jeopardise a proper determination of that question unless there is a special inquiry for the purpose.
(4)Schedule 6, which contains further provisions as to Planning Inquiry Commissions, and as to the meaning of “the responsible Minister or Ministers” in subsection (3) and in that Schedule, shall have effect.