 Morgan joined the Labour Party and was elected Member of Parliament for Cardiganshire, Wales at the 1966 general election, and served as a junior minister from 1968 to 1970, as Under-Secretary at the Home Office He was chairman of the Welsh Parliamentary Labour Party between 1971 and 1974.In the February 1974 general election, Morgan lost his seat to the Liberal, Geraint Howells.In 1979 he sought election as Labour candidate for Anglesey, following the retirement of Cledwyn Hughes, but was defeated by the Conservative, Keith Best.