In 1971, firmly on the Right of the Labour Party, Davies was one of the 69 Labour MPs who defied the Labour Whip to vote in favour of entry to the EEC. He campaigned for a 'No' vote in the 1979 referendum in Wales on the establishment of a Welsh Assembly, along with other members of the 'Gang of Six', Neil Kinnock, Leo Abse, Donald Anderson, Alfred Evans and Ioan Evans. Throughout his tenure as MP, he was sponsored by the white-collar trade union APEX.