The party was originally sympathetic to the Labour Party PvdA. Before the party was founded, the group of politically homeless activists had asked to have an independent candidate on their lists. During the 1960s the relation deteriorated, as the PSP rejected the PvdA's moderate course and the PvdA the PSP's radical course. In 1971 the PvdA, which had become more leftwing under pressure of a new generation of party members, opened the door to the PSP. It wanted the PSP to cooperate in the Progressive Accords together with left-liberal Democrats 66 and the PPR. The PSP rejected as it felt these accords would be neither socialist nor pacifist. This decision let to considerable upheaval within the party. In the 1980s as the PvdA became more centrist, the PSP rejected the PvdA even more.