Following the UK referendum last week to leave the EU, calls for opposition leader Jeremy Corbyn to resign started to gain momentum soon after the result. Prime Minister David Cameron resigned on the day after the vote.

The chair of the Parliamentary Labour Party (PLP) agreed that the motion of no confidence forwarded by MPs Margaret Hodge and Ann Coffey be debated at a meeting of MPs on 27 June and then put to the vote the next day. Almost 60 former Labour parliamentary candidates have also called for their leader to resign.

The majority of the leadership of both main parties - including Corbyn and Conservative Party chief Cameron - had supported the "Remain" camp ahead of the vote.

Shadow cabinet shake-up

Over half of Corbyn's 32-strong shadow cabinet were sacked or have quit since the UK's Brexit referendum. Shadow Foreign Minister Hilary Benn was the first to go, with a reportedly unwilling Corbyn sacking him by phone on Saturday evening.

Further resignations included even some loyal members of his team on the left of the party, including Shadow Business Secretary Angela Eagle, Shadow Work and Pensions secretary Owen Smith, and the Shadow Energy Secretary Lisa Nandy.

Not quitting

Veteran left-winger Corbyn, however, says he is not quitting, less than a year after he was elected by well over 50 percent of the party's membership.

Labour had lost the 2015 general election under the helm of Corbyn's predecessor Ed Miliband, amid a period of austerity that has hit many in its traditional industrial strongholds in the north of England, Wales and Scotland.

The 66-year-old republican stood for the leadership vacuum as an outsider - with the odds considered to be strongly against him at the time.

"I was elected by hundreds of thousands of Labour party members and supporters with an overwhelming mandate for a different kind of politics," Corbyn said in a statement.

An unspecified source close to Corbyn was quoted saying in "The Times" newspaper that the shadow cabinet was now stronger.

"There is no shortage of good people who want to do these jobs. The only way to try to replace Jeremy is to stand against him in a democratic contest,” the unnamed source told the newspaper.

Internecine Labour fights

Corbyn has been attacked by many within his own party since coming to power in 2015. Many have criticized him for his failure - as they see it - to push Labour's working class hinterland to back the Remain vote in last week's referendum.

His apparent disregard for conventional politics, failing to take a tough public stance on a raft of issues from the economy to the EU referendum, has - according to his critics - damaged Labour's competitiveness with other parties.

However, Corbyn's supporters have also mobilized, with the Momentum group - a key Corbyn grouping within the Labour movement - organizing a large protest in Westminister on the evening of June 27, at which Corbyn spoke, although not mentioning the no-confidence vote he’s facing.

Who would take over?

Shadow Minister for the Cabinet Office Tom Watson is now reportedly "waiting in the wings" to make a leadership challenge. In a statement broadcast on Sky News he "seemed to position himself as a caretaker leader who could prepare Labour to fight an imminent general election."

William Hill bookmakers are offering odds of 7/2 for Watson, with Hilary Benn, the former shadow business secretary Chuka Umunna and former British Army major Dan Jarvis joint second favorites. Two prominent women - Jess Phillips and Caroline Flint - are priced at 40/1.