77.—(1) The revocation or variation pursuant to regulation 75 of an authorisation under the Pipe–lines Act 1962, or of a direction deeming planning permission to be granted, shall take effect upon service of the notices required by regulation 76(1) or, where there is more than one such notice and those notices are served at different times, upon the service of the last such notice to be served.
(2) Where the Secretary of State decides not to proceed with the revocation or variation, the authorisation or direction shall have effect again from the time of that decision, and shall thereafter have effect as if–
(a)any period specified in the authorisation or direction for the taking of any action, being a period which had not expired prior to the date mentioned in paragraph (1), were extended by a period equal to that during which the revocation or variation had effect; and
(b)there were substituted for any date specified in the authorisation or direction as being a date by which any action should be taken, not being a date falling prior to that date mentioned in paragraph (1), such date as post–dates the specified date by a period equal to that during which the revocation or variation had effect.
(3) The revocation or variation pursuant to regulation 75 of an authorisation under the Pipe–lines Act 1962, or a direction deeming planning permission to be granted, shall not affect anything done under the authorisation or direction prior to the revocation or variation taking effect.