Until 1971 the Belgian Socialist Party (BSP) was the only political, party that closely and systematically involved its members in the designation of socialist candidates for parliamentary elections. This was achieved through a system of pre-elections within the party («polling»).The trend away from «polling», already perceptible in 1971, has asserted itself in 1974. Hardly 56 % of the elected members of Parliament owe their seat to their place on the candidate-list at the «poll».More than 40 % of them were designated by a party-congress. This change is noticeably true in Flanders.Nevertheless the choice between a «poll» and a congress as a decisionmaking technique is not relevant as to the renewal of parliamentary groups. This renewal is mainly due to the introduction of an age-limit (65) and of a gain in seats. Research also showed a growing lack of interest of party members in the composition of candidate-lists: participation has again slightly declined.