Ed Miliband is stepping down as Labour leader after his party’s disappointing general election showing.
Labour suffered heavy losses at the hands of the SNP, with the Tories forecast to achieve a majority.
In a speech in London, Mr Miliband said it was “time for someone else” to take over the leadership and that he was “truly sorry” he did not succeed reports BBC.
Shadow chancellor Ed Balls was among the party’s big-name casualties.
It also lost its election campaign chief Douglas Alexander and its leader in Scotland Jim Murphy.
Mr Miliband was applauded by staff as he arrived at Labour headquarters in central London.
He confirmed deputy leader Harriet Harman would be interim leader, and that he would step down after the VE Day commemorations later on Friday.
“I joined this party aged 17,” he said. “I never dreamed I’d lead it.”
Nick Clegg has resigned as Liberal Democrat leader after his party was routed at the general election.
The Lib Dems are set to end up with just eight MPs, down from 57 in 2010.
Energy Secretary Ed Davey, Business Secretary Vince Cable and Treasury Secretary Danny Alexander all lost their seats reports BBC.
Mr Clegg said the results were “immeasurably more crushing” than he had feared, saying it had been a “huge honour” to lead the party.
In a speech in London, he confirmed a leadership election would now take place to replace him.
“It’s simply heartbreaking to see so many friends and colleagues who have served their constituents over so many years abruptly lose their seats because of forces entirely beyond their control,” he said.
Mr Clegg, who held seats, added that “fear and grievance have won, liberalism has lost”.
Other senior Lib Dems to fall were former schools secretary David Laws, former party leader Charles Kennedy and former deputy leader Simon Hughes.
Nigel Farage has resigned as leader of UKIP having failed to gain the seat of Thanet South, losing out to Conservative candidate Craig Mackinlay.
But he said he would consider running for the job again when the leadership contest is held in September reports BBC.
Speaking about his defeat, he insisted he had “never felt happier”, with a “weight lifted off his shoulders”.
UKIP has won a 13% vote share in the election and has one MP, Douglas Carswell, who held his Clacton seat.
It puts the party in third place behind the Conservatives and Labour in terms of share of the vote.
Mr Farage said the results proved there needed to be a change to the voting system.
“Personally, I think the first-past-the-post system is bankrupt,” he said.