6(1)Subject to the following provisions of this paragraph, where application for listed building consent is made to a local planning authority, being a London borough council, and the authority do not determine to refuse it, they shall notify the Greater London Council of the application (giving particulars of the works for which the consent is required) and shall not grant such consent unless authorised or directed to do so under sub-paragraph (2) of this paragraph.
(2)On receipt of notification under sub-paragraph (1) of this paragraph the Greater London Council may either—
(a)authorise the local planning authority to grant or refuse the application, as they think fit; or
(b)give them directions as to how they are to determine it.
(3)The Greater London Council shall not authorise the local planning authority as mentioned in sub-paragraph (2)(a) of this paragraph, nor under sub-paragraph (2)(b) of this paragraph direct them to grant listed building consent, unless the Council have notified the Secretary of State of the application made to the local planning authority (giving particulars of the works for which the consent is required) and either—
(a)a period of twenty-eight days has expired, beginning with the date of the notification, without the Secretary of State having directed the reference of the application to him ; or
(b)the Secretary of State has notified the Council that he does not intend to require the reference of the application.
(4)The Secretary of State may at any time before the said period of twenty-eight days expires give notice to the Council that he requires further time in which to consider whether to require the reference of the application to him and sub-paragraph (3) of this paragraph shall then have effect with the substitution for the period of twenty-height days of such longer period as may be specified in the Secretary of State's notice.