It was the result of the division of the Socialist Party of Chile in 1948 by voting and promulgation of Law No. 8,987 of Defense of Democracy in which the PS was divided in its vote and support among pro-communist and anti-communist.
Foi o resultado da división do Partido Socialista de Chile en 1948 pola votación e promulgación da Lei N° 8.987 de Defensa da Democracia na cal o PS se dividiu entre procomunista e anticomunistas.