3(1)A commission inquiring into a matter referred to them under section 101 shall—
(a)identify and investigate the considerations relevant to, or the technical or scientific aspects of, that matter which in their opinion are relevant to the question whether the proposed development should be permitted to be carried out, and
(b)assess the importance to be attached to those considerations or aspects.
(a)in the case of a matter mentioned in section 101(2)(a), (b) or (c), the applicant, or
(b)in any case, the local planning authority,
so wish, the commission shall give to each of them, and, in the case of an application or appeal mentioned in section 101(2)(a) or (b), also to any person who has made representations relating to the subject matter of the application or appeal which the authority are required to take into account under section 71(1) or (2), an opportunity of appearing before and being heard by one or more members of the commission.
(3)The commission shall then report to the responsible Minister or Ministers on the matter referred to them.
(4)A commission may, with the approval of the Secretary of State and at his expense, arrange for the carrying out (whether by the commission themselves or by others) of research of any kind appearing to them to be relevant to a matter referred to them for inquiry and report.
(5)In sub-paragraph (4) “the Secretary of State,” in relation to any matter affecting both England and Wales, means—
(a)the Secretary of State for the time being having general responsibility in planning matters in relation to England, or
(b)the Secretary of State for the time being having responsibility in relation to Wales,
acting, by arrangements between the two of them, on behalf of both.