26.—(1) A person who ceases to meet any of conditions A to C in regulation 21 in an employment or is prevented by regulation 22 or 23 from continuing to be an active member in an employment must cease to be an active member of the Scheme in that employment.
(2) Accordingly—
(a)a person within paragraph (1) may not make any further contributions to the Scheme under Chapter 3, and
(b)any further service of the person is not pensionable service for the purposes of the Scheme.