The leaders of Britain's three main political parties criss-crossed the country yesterday in a last-minute scramble for support with polls suggesting that millions remained undecided how to vote in today's knife-edge election.

Gordon Brown, the prime minister and Labour leader, appeared to have gained renewed momentum in the final days of the campaign looking as though he may have avoided the humiliation of coming third today behind Nick Clegg's Liberal Democrats, traditionally the third placed party.

However, it was far from clear that David Cameron, Conservative leader, would win a decisive majority of the House of Commons tonight, with many voters still uncertain over whether to back his claim that the Tories represent the chance of a fresh start for the UK.