(1)Before the powers conferred by section 21 become exercisable by virtue of an authorisation, the senior police officer who gave the authorisation shall ensure that an authorisation notice is—
(a)published in a newspaper circulating in the relevant locality; and
(b)displayed in some conspicuous place or places within the relevant locality.
(2)An “authorisation notice” is a notice which—
(a)states that authorisation has been given;
(b)specifies the relevant locality; and
(c)specifies when the powers may be exercised.
(3)An authorisation may be withdrawn by—
(a)the senior police officer who gave it; or
(b)any police officer whose police area includes the relevant locality and whose rank is the same as or higher than that of the senior police officer mentioned in paragraph (a).
(4)Before withdrawing, under subsection (3), an authorisation, the police officer who proposes to withdraw the authorisation shall ensure that any local authority whose area includes the whole or part of the relevant locality is consulted.
(5)The withdrawal of an authorisation shall not affect the exercise, by virtue of the authorisation, of any power which occurred before the withdrawal.
(6)The giving or withdrawal of an authorisation shall not prevent the giving of a further authorisation in respect of a locality which includes the whole or any part of the relevant locality to which the earlier authorisation relates.
(7)In this section, “authorisation” means an authorisation under section 19.