 Thomas joined the Labour Party in 1919 and was secretary of the Labour Party ward committee in Maesteg.When the SWMF office in Maesteg closed in 1934 Thomas was transferred to the Federation Office in Aberdare as Area Secretary and, in addition, fulfilled the duties of the Miners’ Agent, Noah Ablett, who was seriously ill. On the death of Ablett, he was elected Miners’ Agent, a role he fulfilled until 1946.He worked tirelessly and efficiently on behalf of the miners, dealing with such matters as compensation cases and the rights of the disabled miners.