The Chilean Social Democracy Party (Spanish: Partido Socialdemocracia Chilena (SDCH), until August 1973 Radical Left Party (Partido de Izquierda Radical) was a Chilean political party of centre-left orientation, formed by dissident Radicals in 1971.In its XXV Congress that took place from 31 July to 5 August 1971, the Radical Party confirmed the left-wing line it had taken already in 1967.