(1)Where, by virtue of an order under section 51 of this Act, the use of land for any purpose is required to be discontinued, or any conditions are imposed on the continuance thereof, then if any person, without the grant of planning permission in that behalf, uses the land for that purpose or, as the case may be, uses the land for that purpose in contravention of those conditions, or causes or permits the land to be so used, he shall be guilty of an offence, and shall be liable on summary conviction to a fine not exceeding £400 or on conviction on indictment to a fine; and if the use is continued after the conviction, he shall be guilty of a further offence and liable—
(a)on summary conviction to a fine not exceeding £50 for each day on which the use is so continued; or
(b)on conviction on indictment to a fine.
(2)If, within the period specified in that behalf in an order under section 51 of this Act, any steps required by that order to be taken for the alteration or removal of any buildings or works have not been taken, the local planning authority may, and shall if so required by directions of the Secretary of State, enter the land and take those steps; and section 276 of the [1936 c. 49.] Public Health Act 1936 shall apply in relation to any works executed by a local planning authority under this subsection as it applies in relation to works executed by a local authority under that Act.