[1] It claimed to represent the political legacy of Rodrigo Ambrosio, the principal founder of the original MAPU, who had died in May 1972.

It regarded the formation of the government of Salvador Allende as the principal victory for people and democracy and distanced itself from more extremist left-wing groups like MIR.

It had two ministers in Allende's government (Fernando Flores and Juan Carlos Concha) and a number of other state functionaries were among its ranks.

The MAPU/OC proclaimed that "the Chilean revolution was going through a national democratic phase" and established formal relations with the CPSU and other governing communist parties of the socialist bloc.

The party was more popular among the intellectuals (Tomás Moulián, José Joaquin Bruner, Augusto Varas), university students (who in 1976 founded the Unión de Jóvenes Democráticos) and peasants (the leaders of the Confederación Unidad Obrero Campesina).