B4.—(1) A person who would be or become a pensionable employee in accordance with these regulations but for a notification under regulation B3 may, notwithstanding the giving of that notification but subject to paragraphs (3) and (4), subsequently elect so to become a pensionable employee.
(2) An election under paragraph (1) shall be made by notice given in writing to the body which is to become the person’s employing authority.
(3) A person who has made an election under paragraph (1) and who subsequently gives another notification under regulation B3(1) may, subject to paragraph (4), make no further election under paragraph (1).
(4) Notwithstanding paragraph (3), a person may elect under paragraph (1) whenever he begins employment which might fall within regulation B1 with a different employing authority, provided the notice of election is given to that employing authority before or within the period of 3 months beginning with the day on which he begins that employment.
(5) Regulation B2(3) to (6) shall apply to an election under paragraph (1) as it applies to an election under regulation B2(1).