 Barnes also voted in favour of the UK joining the EEC, rebelling against a Labour three line whip.Barnes remained an MP until 1974, when the Brentford and Chiswick seat was abolished in boundary changes.At the February 1974 general election, he stood in the new Brentford and Isleworth constituency against the Conservative MP Barney Hayhoe, whose own Heston and Isleworth constituency had also been abolished.