(1) Subject to subsections (2) and (3), any reference in this Part to existing development means a reference to any development which—
(a) was commenced before the appointed day and was not commenced in contravention of the repealed Act; or
(b) accords with the terms of a permit or development order;
(c) accords with the terms of an approval granted pursuant to an application determined in accordance with paragraph (g) of section seventy-six. (2) Any use or operations referred to in subsection (1) which have ceased for a continuous period of more than two years shall thereafter cease to be regarded for the purpose of this Part as existing development.
(3) Any development referred to in paragraph (a) of subsection (1) which was in contravention of any condition specified in the deed of grant issued in relation to the land concerned shall not be regarded for the purposes of this Part as existing development.