(1) For the purposes of subsection (2) of section 125 of the Magistrates' Courts Act 1980 (warrants) and subsection (2) (a) of section 136 of that Act (committal to custody overnight at police station for non-payment of sum adjudged by conviction)—
(a) local authorities, police authorities and magistrates' courts committees are authorities of a prescribed class; and
(b) a person employed by any such authority is authorised in the prescribed manner to execute warrants to which those sections apply within the area for which the authority in question performs its functions if he has been issued by or on behalf of the authority by which he is employed with an authorisation in writing in that behalf in a form suitable for identifying him to persons with whom he deals as a person so authorised.
(2) In paragraph (1) above, “local authorities” means—
(a) a district council,
(b) a London borough council, and
(c) a county council.