Liberal Democrat leader Nick Clegg has mounted an ambitious raid on Labour's northern heartlands.
Mr Clegg took his campaign to three of the Lib Dems' Labour-held target seats - Burnley, Colne Valley, and Redcar, where they would need to overturn a 12,000 majority. In a pitch to Labour voters, he accused the party of having "betrayed" its natural supporters during its 13 years in office.
With just four days to polling, the three main party leaders were all engaged in a frenetic day of campaigning as they began the final push for votes in an election where the outcome remains highly uncertain.
Gordon Brown was concentrating his fire on the Tories - denouncing their manifesto as a "horror show".
His attack was echoed by Northern Ireland Secretary Shaun Woodward, who said the country was in danger of "sleepwalking into a living nightmare - that nightmare is David Cameron's divided Britain".
Tory leader David Cameron acknowledged that the Conservatives would have to go further in cutting public spending than they had so far admitted in order to tackle Britain's record £163 billion deficit. But he insisted that he would ensure that the most vulnerable in society were protected.
