8.1. For the purposes of the application of section 99.9.4 of the Act, the agreement between the civil servant and his employer becomes void by reason of any of the following circumstances:(1) the time worked is less than 40% of the regular time of a full-time civil servant holding such a position;
(2) the civil servant voluntarily ceases to participate in this plan during the first year of his participation in the agreement;
(3) a civil servant eligible for a pension does not cease participating in this plan on the expiry of the period agreed upon.