Where a member of a local authority—
(a) ceases to be qualified to be a member of the authority; or
(b) becomes disqualified for being a member of the authority otherwise than under section 80A(1)(c) of this Act, section 79 of the Local Government Act 2000 or section 34 of the Localism Act 2011 or by virtue of, a conviction or a breach of any provision of Part II of the Representation of the People Act 1983 , or by virtue of an order under section 30 of the Elections Act 2022; or
(c) ceases to be a member of the authority by reason of failure to attend meetings of the authority;
the authority shall, except in any case in which a declaration has been made by the High Court under this Part of this Act, forthwith declare his office to be vacant.
In this section "local authority" includes a joint authority , an economic prosperity board , a combined authority and a combined county authority ...