s 70C Power to decline to determine retrospective application
(1) A local planning authority ... may decline to determine an application for planning permission or permission in principle for the development of any land if granting planning permission for the development would involve granting, whether in relation to the whole or any part of the land to which a pre-existing enforcement notice relates, planning permission in respect of the whole or any part of the matters specified in the enforcement notice as constituting a breach of planning control. (2) For the purposes of the operation of this section in relation to any particular application for planning permission or permission in principle , a “pre-existing enforcement notice” is an enforcement notice issued before the application was received by the local planning authority.