2(1)Planning permission granted by virtue of paragraph 1 is subject to the condition that development is carried out in accordance with such requirements as the Secretary of State may by notice to the developer specify for the purpose of—U.K.
(a)avoiding a breach of an undertaking given by the Secretary of State to the Select Committee of either House of Parliament to which the High Speed Rail (West Midlands - Crewe) Bill was committed, or
(b)securing that the environmental effects of carrying out the development are not materially different from those envisaged by the statement by virtue of which paragraph 1(1)(b) applies.
(2)The power conferred by sub-paragraph (1) is exercisable after, as well as before, development is commenced.
(3)The power conferred by sub-paragraph (1) includes power, exercisable in the same manner, to vary or revoke a notice under that sub-paragraph.
(4)The condition imposed by sub-paragraph (1) is in addition to any condition to which the planning permission may be subject apart from this paragraph.