6.—(1) Subject to paragraph (3), if planning permission is granted under the powers conferred by the 1990 Act for development any part of which is within the Order limits following the coming into force of this Order that is not—
(a)itself a nationally significant infrastructure project under the 2008 Act or part of such a project; or
(b)required to complete or enable the use or operation of any part of the development authorised by this Order,
then the construction, maintenance, use or operation of that development under the terms of the planning permission does not constitute a breach of the terms of this Order.
(2) Except as expressly provided, nothing in this Order is to prejudice the operation of, and the powers and duties of the undertaker under, the 1980 Act, the 1991 Act and the Town and Country Planning (General Permitted Development) (England) Order 2015(1).
(3) Within the World Heritage Site, the undertaker may not rely on planning permission granted by class B of Part 9 (development relating to roads) of Schedule 2 (permitted development rights) of the Town and Country Planning (General Permitted Development) (England) Order 2015 for any part of the authorised development.