Validity of decisions
5. After section 105C of the 1980 Act insert the following section—

“Validity of decisions
105D. (1) If a person aggrieved by a decision of the Secretary of State to proceed with the construction or improvement for which an environmental statement has been made desires to question the validity of the decision on the ground that—
(a) it is not within the powers of this Act; or
(b) any requirement of this Part of this Act has not been complied with in relation to the decision;
he may, within 6 weeks from the date on which the decision is first published under section 105B (6), make an application for the purpose to the High Court.
(2) On any such application, the Court—
(a) may by interim order suspend the operation of the decision, or any aspect of it, either generally or in so far as it affects any property of the applicant, until the final determination of the proceedings; and
(b) if satisfied that the decision is not within the powers of this Act, or that the interests of the applicant have been substantially prejudiced by a failure to comply with any requirement of this Part of this Act, may quash the decision or any aspect of it, either generally or in so far as it affects any property of the applicant.
(3) Subject to subsection (2), a decision to which subsection (1) applies shall not be questioned in any legal proceedings whatever.”.