10.—(1) The electoral divisions of Durham comprised in Darlington shall cease to be electoral divisions on the reorganisation date; and any person holding office, immediately before that date, as a councillor for such a division shall retire on that date(1).
(2) Section 89 of the 1972 Act (filling of casual vacancies in case of councillors) shall have effect—
(a)in the case of a casual vacancy occurring in the office of councillor of the Darlington Council during the period beginning with the date on which this article comes into force and ending with the relevant date, as if the reference in subsection (3) of that section to the day on which the councillor whose office is vacant would regularly have retired were a reference to the relevant date; and
(b)in the case of a casual vacancy occurring in the office of councillor for any electoral division referred to in paragraph (1) above, as if that reference in that subsection were a reference to the reorganisation date.
The electoral divisions of the county of Durham are constituted by the County of Durham (Electoral Arrangements) Order 1981 (S.I.1981/190).