 As a student he joined the Italian Socialist Party (Partito Socialista Italiano, PSI).Forced to leave Venice by the Fascists after Mussolini’s March on Rome in October 1922, he went to Rome and then Milan, where he helped organise the Third Internationalist’ faction of the PSI.In the summer of 1924 he adhered to the Italian Communist Party (Partito Comunista Italiano, PCI).