The KPÖ held a line which was often in disagreement with the Communist Party of the Soviet Union, such as disagreeing with Stalin's branding of social democracy as a form of "social fascism" in the late 1920s. The Austrian communists dissent was avant-garde, with their refusal to condemn Social Democracy reflecting aspects of the 7th World Congress of the Comintern in 1935. The Austrian communists' tolerant stance opened their party to an influx of more disappointed Social Democrats. After the crushing of the February 1934 uprising by the federal army and the "Heimwehr", the KPÖ grew rapidly from 4,000 to 16,000 members.