Exercise on behalf of fire inspectors etc. of their powers by officers of fire brigades
28.—(1) The powers conferred by article 27 on a fire inspector, or any other person authorised by the Secretary of State under article 25(e), are also exercisable by an employee of the fire and rescue authority when authorised in writing by such an inspector for the purpose of reporting to him on any matter falling within his functions under this Order; and articles 27(2) and (3) and 32(2)(d) to (f), with the necessary modifications, apply accordingly.
(2) A fire inspector, or other person authorised by the Secretary of State, must not authorise an employee of a fire and rescue authority under this article except with the consent of the fire and rescue authority.
What the Guidance says: