For the purpose of securing, so far as is reasonably practicable, a uniform statutory code applicable throughout any part of Great Britain, the Secretary of State may by order provide for the amendment or repeal of any local enactment, regulation or order to which paragraph 19 above applies, or for its extension to any area specified in the order, and for such matters consequential on or incidental to any such amendment, repeal or extension for which the Secretary of State considers it necessary or expedient to provide.