Subject to the provisions of this section, where an enforcement notice has been served on the person who, at the time when the notice was served on him, was the owner of the land to which it relates, then, if any steps required by the notice to be taken (other than the discontinuance of a use of land) have not been taken within the period allowed for compliance with the notice, that person shall be liable on summary conviction to a fine not exceeding £400 or on conviction on indictment to a fine.
If a person against whom proceedings are brought under subsection (1) of this section has, at some time before the end of the period allowed for compliance with the notice, ceased to be the owner of the land, he shall, upon information duly laid by him, and on giving to the prosecution not less than three clear days' notice of his intention, be entitled to have the person who then became the owner of the land (in this section referred to as "the subsequent owner") brought before the court in the proceedings.
If, after it has been proved that any steps required by the enforcement notice have not been taken within the period allowed for compliance with the notice, the original defendant proves that the failure to take those steps were attributable, in whole or in part, to the default of the subsequent owner—
(a) the subsequent owner may be convicted of the offence; and
(b) the original defendant, if he further proves that he took all reasonable steps to secure compliance with the enforcement notice, shall be acquitted of the offence.
If, after a person has been convicted under the preceding provisions of this section, he does not as soon as practicable do everything in his power to secure compliance with the enforcement notice, he shall be guilty of a further offence and liable—
(a) on summary conviction to a fine not exceeding £50 for each day following his first conviction on which any of the requirements of the enforcement notice (other than the discontinuance of the use of land) remain unfulfilled; or
(b) on conviction on indictment to a fine.
Where, by virtue of an enforcement notice, a use of land is required to be discontinued, or any conditions or limitations are required to be complied with in respect of a use of land or in respect of the carrying out of operations thereon, then if any person uses the land or causes or permits it to be used, or carries out those operations or causes or permits them to be carried out, in contravention of the notice, 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 on summary conviction to a fine not exceeding £50 for each day on which the use is so continued, or on conviction on indictment to a fine.
Any reference in this section to the period allowed for compliance with an enforcement notice is a reference to the period specified in the notice for compliance therewith or such extended period as the local planning authority may allow for compliance with the notice.