When, or at any time after, an enforcement notice is served on a person, the local planning authority may give the person a letter—
At any time after a person has under subsection (1) been given a letter containing an assurance, the local planning authority may give the person a letter withdrawing the assurance (so far as not previously withdrawn) in full or part from a time specified in the letter.
The time specified in a letter given under subsection (2) to a person must be such as will give the person a reasonable opportunity to take any steps necessary to avoid any risk of prosecution that is to cease to be covered by the assurance.
Withdrawal under subsection (2) of an assurance given under subsection (1) does not withdraw the assurance so far as relating to prosecution on account of there being a time before the withdrawal when steps had not been taken or an activity had not ceased.
An assurance given under subsection (1) (so far as not withdrawn under subsection (2)) is binding on any person with power to prosecute an offence under section 179.