Where an interest in land is held by statutory undertakers for the purpose of the carrying on of their undertaking and—
then the following subsection shall have effect for the purpose of determining whether the land is to be so treated and shall so have effect notwithstanding the definition of " operational land " in section 221(1) of the principal Act.
The land shall not be treated as operational land for the purposes of the principal Act unless one or both of the following conditions are satisfied with respect to it, namely—
A specific planning permission for the purpose of subsection (2)(a) above is a planning permission—
and the reference in paragraph (b) of this subsection to development which has received specific parliamentary approval shall be construed as referring to development authorised by a local or private Act of Parliament or by an order approved by both Houses of Parliament or by an order which has been brought into operation in accordance with the provisions of the Statutory Orders (Special Procedure) Act 1945, being an Act or order which designates specifically both the nature of the development thereby authorised and the land upon which it may be carried out.