Labour is set to win a comfortable majority in Thursday's British general election, according to a new poll for the Financial Times, after the opposition Conservatives appeared to suffer a setback in the latest stages of their campaign.

According to Mori's final poll for the FT, Labour has a 39 per cent share of the vote among those absolutely certain to cast a ballot on Thursday, 10 points ahead of the Conservatives, with Britain's third party - the Liberal Democrats - on 22 per cent.