Where it appears to a local authority that any authority ... mentioned in subsection (3) could, by taking any specified action, help in the exercise of any of their functions under this Part, they may request the help of that other authority ... specifying the action in question.
An authority whose help is so requested shall comply with the request if it is compatible with their own statutory or other duties and obligations and does not unduly prejudice the discharge of any of their functions.
The authorities are—
any local authority;
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
any local housing authority;
NHS England;
any integrated care board, Local Health Board, Special Health Authority ... , National Health Service trust or NHS foundation trust;
any local authority in Wales; and
any person authorised by the Secretary of State for the purposes of this section.
The Secretary of State must not authorise the Welsh Ministers under subsection (3)(e) without their consent.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .