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.
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.
Mr Davey, previously tipped as a possible party leader, lost his Kingston and Surbiton seat to the Conservatives.
Nearby in south west London, Mr Cable lost his Twickenham seat, also to the Conservatives.
Both attributed their defeats to a combination of coalition and Conservative warnings about the threat of a Labour/Scottish National Party administration.
‘Paid the price’
Mr Davey said his party had “paid some price” for joining a coalition government but he had “lost on Conservative warnings” of a Labour government propped up by the SNP.
Mr Cable said it had been “a terrible night”, but the party would “bounce back”.
Source: BBC