29.1. The payment of a pension granted by virtue of the general plan ceases, upon request from the beneficiary, if he again becomes a member of the council of a municipality which has joined the general plan.
In such case, he contributes again to the general plan and the pension he was receiving is computed again when he ceases to hold office in order to take into account the credited service and the pensionable salary credited to him while he is holding such office.
If the beneficiary elects to continue to receive his pension, he does not contribute to the general plan.