7. Where immediately before the commencement date a member was eligible to make an election under regulation E2(9)(c) of the 1987 Regulations by reason of having re-entered local government employment in the period of three months ending at that time, but had not done so–
(a)he may make an election under regulation 31(1) of the 1998 Regulations at any time whilst he remains an active member in that employment; but
(b)if he does not make such an election before he ceases to be such a member in that employment, he shall be treated for the purposes of these Regulations as if he had made an election under regulation E2(9)(c) of the 1987 Regulations immediately before the commencement date as respects all the membership as to which he could have made that election.