Phil Thorne was born in Melbourne in 1908 and was employed as a solicitor’s clerk until 1927. Following a period of farming in Queensland, he became a clerk in the offices of Jack Wishart, a Sydney solicitor interested in social causes. In late 1930 he joined the Friends of the Soviet Union and was a member of International Class-War Prisoners Aid. Thorne was editor of Labour Defender, the journal of the International Labour Defence, and in 1936 was elected Secretary of the Spanish Relief Committee, an organisation formed in Sydney on 26 August 1936 by the Movement Against War and Fascism and the International Labour Defence. Thorne was active in the SRC until it disbanded at the outbreak of World War II.