David Cameroon's conservatives on course for majorityDavid Cameron says he hopes to govern for all of the UK as a BBC forecast gives the Tories 329 seats - enough to form a slender majority in the Commons.
His party made gains in England and Wales, including taking Ed Balls' seat.
Two senior Labour sources have told the BBC that Ed Miliband is expected to stand down later after Labour was all but wiped out by the SNP in Scotland.
The Lib Dems are heading for as few as eight MPs, with Vince Cable, Ed Davey and Danny Alexander losing their seats.
The BBC forecast, with 635 of 650 seats declared, is Conservative 329, Labour 234, the Lib Dems eight, the SNP 56, Plaid Cymru three, UKIP one, the Greens one and others 19.
The Conservatives are expected to have won a 37% share of the national vote, Labour 31%, UKIP 13%, the Lib Dems 8%, the SNP 5%, the Green Party 4% and Plaid Cymru 1%.