Sch A1 para 90
(1) This paragraph applies if— (a) the CAC decides an appropriate bargaining unit or units under paragraph 70 or 79, and (b) at least one worker falling within the original unit does not fall within the new unit (or any of the new units). (2) In such a case — (a) the CAC must issue a declaration that the bargaining arrangements, so far as relating to the worker or workers mentioned in sub-paragraph (1)(b), are to cease to have effect on a date specified by the CAC in the declaration, and (b) the bargaining arrangements shall cease to have effect accordingly.