 Together with Emrys Jones, Regional Organiser for the Wales Labour Party, and Gwyn Morgan, Assistant General Secretary to the UK Party, he drafted Labour's evidence to the Crowther/Kilbrandon Royal Commission on the Constitution.In 1970, at the age of 27, he was elected Member of Parliament (MP) for Carmarthen, defeating the president of Plaid Cymru, Gwynfor Evans, with a majority of 3,600 votes.He held on to the seat by just 3 votes (with five recounts) in the February 1974 general election, but lost the seat back to Evans by 3,640 votes in the October election of that year.