5.—(1) A declaration shall, subject to sub-paragraph (2) remain in force for such period as is specified in the declaration or, where no period is so specified, for a period of 10 years from the date of the issue of the declaration.
(2) At any time, whether before or after the expiration of the period for which a declaration is in force, the county court, on application made to it by the housing authority or by any person who has acquired a site specified in the declaration, may, after hearing the objections, if any, made by virtue of sub-paragraph 3(3), order—
(a)where the application is made by the housing authority, that the declaration shall continue to be in force in relation to all the sites specified in the declaration or to such of those sites as the court thinks fit; or
(b)where the application is made by a person who has acquired an estate in a site specified in the declaration, that the declaration shall continue to be in force in relation to that site,
for such period as the court thinks fit.
(3) Paragraph 3 shall apply in relation to applications for orders under sub-paragraph (2) as if references to a declaration were references to such an order and as if references to a housing authority included references to a person who has acquired an estate in a site with respect to which an application under sub-paragraph (2) is proposed to be made.