In 1928, Buck was expelled from the International Association of Machinists for being a member of the Communist Party of Canada.Rodney, William. Soldiers Of The International; A History of the Communist Party of Canada, 1919–1929. Victoria, British Columbia. University of Toronto Press (1968) P.137 With the onset of the Great Depression, the Conservative government of R. B. Bennett became increasingly worried about left-wing activity and agitation. On August 11, 1931, the Communist Party offices in Toronto were raided, and Buck and several of his colleagues were arrested and charged with sedition. Buck was tried in November, convicted of sedition and sentenced to hard labour.
