s 286 Challenges to validity on ground of authority’s powers.
(1) The validity of any permission, determination or certificate granted, made or issued or purporting to have been granted, made or issued by a local planning authority in respect of— (a) an application for planning permission or permission in principle ; (aa) an application for non-material changes to planning permission under section 96A; (b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (c) an application for a certificate under section 191 or 192 ; (d) an application for consent to the display of advertisements under section 220; or (e) a determination under section 302 or Schedule 15, shall not be called in question in any legal proceedings, or in any proceedings under this Act which are not legal proceedings, on the ground that the permission, determination or certificate should have been granted, made or given by some other local planning authority. (2) The validity of any order under section 97 revoking or modifying planning permission or permission in principle , any order under section 102 or paragraph 1 of Schedule 9 requiring discontinuance of use, or imposing conditions on continuance of use, or requiring the alteration or removal of buildings or works, or any enforcement notice under section 172 or stop notice under section 183 or a breach of condition notice under section 187A , being an order or notice purporting to have been made, issued or served by a local planning authority, shall not be called in question in any such proceedings on the ground— (a) in the case of an order or notice purporting to have been made, issued or served by a district planning authority, that they failed to comply with paragraph 11(2) of Schedule 1; (b) in the case of an order or notice purporting to have been made, issued or served by a county planning authority, that they had no power to make, issue or serve it because it did not relate to a county matter within the meaning of that Schedule. (3) The validity of any completion notice served or purporting to have been served by a local planning authority under section 93H shall not be called in question in any legal proceedings, or in any proceedings under this Act which are not legal proceedings, on the ground of non-compliance with any requirement of paragraph 10 of Schedule 1.