DS'70 was founded on 4 April 1970 as the result of a split from the Labour Party (PvdA). In June 1970, two members of the House of Representatives, Goedhart and Schuitemaker, left the PvdA and became members of DS'70, because of the anti-American position the PvdA had taken in the Vietnam war. They had previously been frustrated by its cooperation with other left-wing parties, such as the Pacifist Socialist Party, and its left-wing fiscal policy. In the 1972 election, the party lost two seats, and it was confined to opposition to the PvdA-headed Den Uyl cabinet.