http://www.legislation.gov.uk/id/uksi/1994/2716

SCHEDULE 1PROCEDURE IN CONNECTION WITH ORDERS UNDER REGULATION 22

Restriction on power to amend orders or confirm them with modifications

5.

The Secretary of State shall not by virtue of paragraphs 3(1) or 4(2) amend an order which has taken effect, or confirm any other order with modifications, so as to extend the area to which the order applies.