6.—(1) An individual elected as mayor at the first election shall come into office on the fourth day after the election and, unless he resigns or otherwise ceases to hold office, shall hold office, subject to paragraphs (3) to (5), until the fourth day after the second election (when his successor comes into office).
(2) An individual elected as mayor at an election other than the first election shall come into office on the day that his predecessor retires and, unless he resigns or otherwise ceases to hold office, shall hold office, subject to paragraphs (3) to (5), until his successor comes into office.
(3) Where the result of a referendum held by an authority whose existing arrangements involve an elected mayor is to approve proposals for different arrangements involving an elected mayor, the elected mayor under the existing arrangements shall hold office until the fourth day after the day on which an individual is elected as the elected mayor under the different arrangements.
(4) Where the result of a referendum held by an authority whose existing arrangements involve an elected mayor is to approve proposals—
(a)for different arrangements that do not involve an elected mayor; or
(b)for alternative arrangements(1),
the elected mayor under the existing arrangements shall hold office until the fourth day after the date on which, but for this paragraph, a second or subsequent election would have been held in accordance with regulation 3 or regulation 5, respectively.
(5) Where the majority of the votes cast in a further referendum are “no ” votes, the elected mayor under the existing arrangements shall hold office until the day on which the authority implement their fall-back proposals in accordance with paragraph (6) of regulation 21 (determination of referendum petitions, and subsequent procedures) of the Referendums Regulations.
See sections 32(1) and 48(1) of the Local Government Act 2000.