A brilliant though often abrasive orator, he was MP for Ebbw Vale 1929–60. His most notable contribution was the creation of the National Health Service (1948) during his time as Minister of Health (1945–51). He resigned from the government in protest against the introduction of health-service charges. The leader of the left wing of the Labour Party, he was defeated by Hugh Gaitskell in the contest for the party leadership in 1955.