A string of members of Jeremy Corbyn's shadow cabinet have quit and Hilary Benn has been sacked. Here's a quick guide to who's going and who remains in Labour's top team.
MPs who have left shadow cabinet:
Shadow foreign secretary Hilary Benn (sacked)
Hilary Benn was sacked as shadow foreign secretary after he phoned Jeremy Corbyn and told him he had lost confidence in his ability to lead the party.
He told the BBC it had been a "very difficult decision" to tell Mr Corbyn he no longer had confidence in him. But he added that Labour needed "strong and effective leadership".
"We don't currently have that and there is also no confidence that we will be able to win a general election as long as Jeremy remains leader."
Mr Benn, the MP for Leeds Central, had disagreed with Jeremy Corbyn in September over air strikes on Syria. He served as a minister in both the Blair and Brown governments and was in Ed Miliband's shadow cabinet.
Shadow health secretary Heidi Alexander (resigned)
A former party whip under Ed Miliband's leadership, the MP for Lewisham East has a lower profile than Mr Benn outside Westminster.
Made shadow health secretary in Jeremy Corbyn's first shadow cabinet, she was categorised as "neutral but not hostile" to Mr Corbyn in a list of Labour MPs leaked to The Times in March.
But in a letter on Sunday, she said she was resigning with a "heavy heart" from the shadow cabinet following the referendum result: "As much as I respect you as a man of principle, I do not believe you have the capacity to shape the answers our country is demanding and I believe that if we are to form the next government, a change of leadership is essential."
Shadow minister for young people and voter registration Gloria De Piero (resigned)
The former GMTV reporter has resigned. According to the Guardian, in her letter to Mr Corbyn she told him: "I do not believe you can deliver... victory at a general election, which may take place in a matter of months.
"I have been contacted by many of my members this weekend and it is clear that a good number of them share that view and have lost faith in your leadership."
She has represented Ashfield since the 2010 general election and held various shadow ministerial roles under Ed Miliband.
Shadow secretary of state for Scotland Ian Murray (resigned)
Edinburgh South MP Ian Murray, the only current Labour MP in Scotland, has resigned as shadow Scotland secretary.
Mr Murray told the BBC it had been an "incredibly difficult decision" but the sacking of Hilary Benn had been "the final straw for me".
He said Mr Corbyn was a "decent human being" and was "principled" but said ultimately: "He can't lead the Labour Party in a general election because he's not likely to win."
He said the party must widen its appeal outside its "comfort zone". He had continued as shadow Scottish secretary under Mr Corbyn, having initially been given the role by acting leader Harriet Harman in May 2015.
Shadow education secretary Lucy Powell (resigned)
The Manchester Central MP has confirmed that she has resigned "with regret" from the shadow cabinet.
In a letter to Mr Corbyn, she said: "It is increasingly clear that your position is untenable and that you are unable to command the support of the shadow cabinet, the Parliamentary Labour Party and, most importantly, the country... I do not have the confidence that you can bring the party together, lead us to a general election and be an effective opposition."
Elected in 2012, Ms Powell was a close ally of Ed Miliband and was vice-chair of Labour's general election campaign.
During the 2015 Labour leadership campaign she said she had "never, ever met or spoken to" Mr Corbyn since becoming an MP.
Shadow environment secretary Kerry McCarthy (resigned)
The Bristol East MP said in her resignation letter that a new leader was needed "to take on the challenges ahead, steering our way through the very difficult period facing this country".
First elected in 2005, she had previously shadowed positions in the Foreign Office, Treasury and Department for Work and Pensions. She is also a vegan and campaigns on food issues.
Shadow chief secretary to the Treasury Seema Malhotra (resigned)
Seema Malhotra, John McDonnell's number two in the shadow Treasury team, wrote to Mr Corbyn that she was proud to have served in his top team but said the Labour Party was now "hugely divided" and those divisions were growing.
"I have come to the view that under your leadership we will not be able to build bridges across the party."
MP for the London seat of Feltham and Heston since a 2011 by-election, she was made shadow minister for preventing violence against women and girls by the then Labour leader Ed Miliband.
Shadow transport secretary Lilian Greenwood (resigned)
The Nottingham South MP told the BBC she had had "concerns and doubts" about Mr Corbyn's leadership for a while but the prospect of a snap general election had made her think about whether she could ask voters to back him for prime minister.
"Sadly I don't think Jeremy is in a position to provide the leadership that we need to be able to offer the voters and the country."
She has represented her constituency since 2010 and was promoted from shadow rail minister under Ed Miliband's leadership.
Shadow Northern Ireland secretary Vernon Coaker (resigned)
The MP for Gedling told the BBC's Sunday Politics East Midlands: "All of us have to consider the positions we hold, to find the best way forward for our party... People are going to have to make quick decisions."
He was shadow Northern Ireland secretary and shadow defence secretary under Ed Miliband and minister for schools under Gordon Brown.
He chaired Yvette Cooper's Labour leadership campaign in the 2015 contest won by Mr Corbyn.
Shadow justice secretary Lord Falconer (resigned)
Lord Falconer was shadow justice secretary - a role to which he had been appointed before Mr Corbyn's election as leader, by acting leader Harriet Harman.
A former flatmate and close ally of former prime minister Tony Blair, he served as Lord Chancellor under the Blair government.
Shadow attorney general Karl Turner (resigned)
Karl Turner, who attended shadow cabinet meetings, has resigned as shadow attorney general "with a very heavy heart".
The MP for Kingston Upon Hull East, a former shadow solicitor general, had replaced Catherine McKinnell who resigned in January, also citing concerns about Labour's direction under Mr Corbyn.
Mr Turner wrote to Mr Corbyn: "It has become increasingly clear that you do not hold the support of the shadow cabinet and the wider Parliamentary Labour Party.
"After the result of the referendum, the country is calling out for strong leadership and opposition to this vicious Tory government.
"At this moment in time I feel like the people of East Hull would be best served if I was to put all of my effort into my constituency work, fighting to make sure that we keep an MP who will stand up for workers' rights as well as the poorest and most vulnerable."
Shadow Commons leader Chris Bryant (resigned)
The MP for Rhondda moved to the shadow Commons role from the job of shadow culture secretary.
He told the BBC Mr Corbyn's management of the referendum campaign "left many voters on polling day not even knowing which way Jeremy himself was going to vote" and that he suspected the Labour leader may have voted to Leave.
Mr Bryant added: "Not only is that a betrayal of Labour's historic position on the European Union - a fundamental economic and foreign policy objective of ours - but also it means that if he were to lead us into a general election, the latest poll shows we would lose 150 seats - we would be a rump of 75 members of Parliament."
Mr Bryant, who backed Yvette Cooper in the leadership contest, has also been the shadow work and pensions, and Home Office, minister. He was offered the job of shadow defence secretary but turned it down because of disagreements with Mr Corbyn on defence policy.
Shadow work and pensions secretary Owen Smith (resigned)
In his resignation letter Mr Smith, the MP for Pontypridd, said: "The communities we seek to represent need a Labour Party that is able to articulate their concerns and most importantly win power to deliver for them".
He also said Jeremy Corbyn could be leading the party towards a formal split - and possibly the emergence of a new party - which Mr Smith said he wanted to avoid.
Mr Smith said he wanted to have a leader who could unite the party.
The former shadow Welsh secretary previously said it was a "great honour" to be appointed to the work and pensions brief. Before entering politics, Mr Smith spent 10 years working as a BBC journalist.
Shadow energy secretary Lisa Nandy (resigned)
The Wigan MP, seen as being on the left of the party, has resigned from the shadow cabinet. Before being made shadow energy secretary she had been a shadow Cabinet Office and education minister.
Left-wing journalist Owen Jones has previously said he considered starting a campaign to make her leader after Ed Miliband.
Ms Nandy said: "The lack of confidence in the leadership goes beyond the small group of MPs who have consistently opposed Jeremy since his election.
"It has become clear that he is unable to form a broad, inclusive shadow cabinet that draws on the best of our movement's left and right traditions."
She said a leadership contest was inevitable and that Tom Watson ought to take over as a caretaker leader.
Shadow secretary of state for Wales Nia Griffith (resigned)
The MP for Llanelli since 2005, Ms Griffith said she had met Mr Corbyn to discuss the leadership of the party but felt the discussions had not given her confidence unity could be achieved in the party.
She said: "I made clear to Jeremy that I have always admired his commitment to the causes that matter to him, but last week's referendum result and the likelihood of an early general election mean that the party now requires new leadership.
"Jeremy has lost the confidence of the party, including many members who initially supported him, and he should now do the honourable thing and resign."
She had also been the shadow minister for Wales under the last leadership and earlier served as a shadow business minister.
Shadow minister for housing and planning John Healey (resigned)
Mr Healey had been shadowing a portfolio he held under Gordon Brown. The Wentworth and Dearne MP held a range of posts during the Labour government, including financial secretary to the Treasury and local government minister.
In his resignation letter he said he had met with Mr Corbyn but was "deeply disappointed with the discussion".
He added that Mr Corbyn was "clearly not prepared to accept the special responsibility you have" in meeting the challenges caused by "unprecedented national uncertainty and lack of government leadership post-Brexit".
Shadow women and equalities minister Kate Green (resigned)
Kate Green said she recognised the mandate Mr Corbyn had from party members, and that he had "energised our politics" since becoming leader. But she said "the most important task we face today as a party is to show the leadership that our country needs".
The former head of the National Council for One Parent Families and the Child Poverty Action group was made a shadow minister by Ed Miliband after entering Parliament in 2010.
The MP for Stretford and Urmston was promoted to the shadow cabinet by Mr Corbyn.
Shadow business secretary Angela Eagle (resigned)
Angela Eagle, who represented the Remain side in some of the EU TV debates, had also been shadow first secretary of state and had deputised for Mr Corbyn at Prime Minister's Questions.
She said the decision to quit had been "agonising", adding: "I have examined my conscience and I have made this personal decision.
"I think it is in the best interests of the Labour Party that Jeremy now examines his conscience and makes a decision to leave with dignity."
The MP for Wallasey stood in the deputy leadership contest and was also a cabinet minister under Gordon Brown. She had previously been tipped as a potential shadow chancellor but was given the business brief instead.
Shadow culture secretary Maria Eagle (resigned)
Maria Eagle is the identical twin sister of the party's now former business spokeswoman, Angela, and has also resigned from her position as shadow culture secretary.
The Garston and Halewood MP was previously shadow defence secretary but had been moved to the less high-profile brief after clashing with Mr Corbyn over the UK's Trident nuclear missile system.
She was also in favour of renewing Trident and voted to support air strikes against Islamic State in Syria.
Shadow minister for mental health Luciana Berger (resigned)
Luciana Berger has resigned as shadow mental health minister. In her resignation letter, which she tweeted a copy of, she said Mr Cobyn had served with "great principle" but added: "We need a Labour leader who can unite our party, both in Parliament and in the country".
The Liverpool Wavertree MP backed Andy Burnham in the leadership election. She was a shadow health minister under Ed Miliband.
Resignations from outside shadow cabinet:
There have also been resignations from outside the shadow cabinet.
Junior frontbenchers including Diana Johnson, Anna Turley, Steve Reed, Yvonne Fovargue, Toby Perkins, Wayne David and Alex Cunningham have resigned and shadow ministerial aides including Stephen Kinnock - the son of former Labour leader Lord Kinnock - also quit.
Sir Keir Starmer, the former director of public prosecutions, resigned as a shadow immigration minister.
MPs still in shadow cabinet:
Shadow chancellor John McDonnell
The veteran Labour left-winger is best friends with Mr Corbyn and co-ordinated his election campaign.
Amid reports of further expected shadow cabinet resignations, he told the BBC rebels should "calm down, listen to their members" and remember a basic principle of the Labour Party, "solidarity".
He said Mr Corbyn had done well in electoral tests so far - by-elections and the local and mayoral elections.
"He's not going anywhere... the support out there is enormous," he said.
He said Mr Corbyn was "not going" as leader and, whatever happened: "I will never stand for leadership of the Labour Party".
He said he and Mr Corbyn had been friends for decades adding: "I will always have his back."
The MP for Hayes and Harlington previously stood for Labour leader in 2007 and 2010.
A prominent rebel under previous Labour leaders, he sparked outrage in 2003 by saying IRA terrorists should be "honoured" for taking part in their "armed struggle", while attending a gathering to commemorate the IRA hunger striker Bobby Sands.
Deputy leader Tom Watson
Mr Watson was at the Glastonbury festival when Mr Benn was sacked and has headed back to London.
Returning to London, he said he was "deeply disappointed" that Hilary Benn had been sacked and "equally saddened" by the shadow cabinet resignations.
He said his focus was on party unity and he would be meeting Mr Corbyn for talks "to discuss the way forward".
The former trade union official entered Parliament in 2001 as MP for West Bromwich. He was a minister under Tony Blair, but resigned in 2006, calling for the then prime minister to quit. He was a Cabinet Office minister and deputy party chairman under Gordon Brown.
Shadow foreign secretary Emily Thornberry
The former shadow defence secretary will replace Hilary Benn as shadow foreign secretary in Mr Corbyn's new cabinet.
Ms Thornberry, who is MP for Islington South, told the BBC it was "extraordinary" that some of her colleagues thought it was the right time for a leadership challenge.
"I'm not going to resign," she said.
She said at "a time like this when the Tory party are pulling themselves apart, when nobody has any idea where the country is going," the Labour Party should "remain unified as a party".
Ms Thornberry was promoted to the shadow cabinet in January 2015 during a protracted reshuffle, which led to the sacking of two leading shadow ministers - Michael Dugher and Pat McFadden - and the resignation of a number of junior spokesmen in protest.
She was a ministerial aide under Gordon Brown and served as shadow attorney general under Ed Miliband.
However, she was sacked in November 2014 after posting a tweet of an image of a white van outside a house bedecked with St George's flags on the eve of the Rochester by-election - a tweet construed to be disparaging and for which she apologised. She nominated Mr Corbyn in the leadership election.
Shadow health secretary Diane Abbott
Another veteran left-winger, Diane Abbott will replace Heidi Alexander, who quit as shadow health secretary.
The former shadow international development secretary is seen as being close to Mr Corbyn and described the resignations as a "kind of Westminster bubble coup" and said they were "not what the party wants".
She said the "coup attempt" was "long-planned" by those opposed to Mr Corbyn's leadership and said it was "disingenuous" to say things had changed because of the EU referendum result.
"Ordinary party members will not understand why Labour MPs want to set themselves at odds with the membership," she said.
Ms Abbott stood in the Labour leadership contest in 2010 - losing to Ed Miliband.
A prominent rebel against the Blair and Brown governments, she voted against the party line on issues including tuition fees and the war in Iraq. She is MP for the east London seat of Hackney North and Stoke Newington.
Shadow lord president of the council and Labour's campaigns and elections director Jon Trickett
Mr Trickett had been shadow communities secretary but was appointed shadow lord president of the council and Labour's campaigns and elections director following resignations from the shadow cabinet.
As news of shadow cabinet resignations came in, Mr Trickett, one of Jeremy Corbyn's most senior backers in the Parliamentary Labour Party, told the BBC News Channel: "If they want to have a contest, let them say who their candidate is, let them say what their programme for Britain is and let's have a leadership contest and let's test the argument."
The MP for Hemsworth said Mr Corbyn "will be on the ballot paper" in any leadership contest.
"There are now hundreds of thousands of party members and I think... let's see what they think about the future."
Mr Trickett is replaced as shadow communities secretary by Grahame Morris, who moved from the whips' office.
Shadow home secretary Andy Burnham
Defeated leadership contender Andy Burnham has tweeted that he will not be resigning, saying he respected the mandate given to Mr Corbyn by party members and adding: "I have never taken part in a coup against any leader of the Labour Party and I am not going to start now."
Mr Burnham, who has announced he will run for mayor of Greater Manchester in 2017, served as chief secretary to the Treasury, culture secretary and health secretary in Gordon Brown's government.
The MP for Leigh - who came fourth out of five contenders in the 2010 leadership contest and came second to Jeremy Corbyn in 2015 - was also previously shadow health secretary.
Chief whip Rosie Winterton
A former government minister for transport, work and pensions and local government at different times under Gordon Brown, the MP for Doncaster Central retained the crucial job of shadow chief whip when Mr Corbyn became leader.
Ms Winterton, a former aide to John Prescott, filled the same role throughout Ed Miliband's leadership.
Shadow leader of the House of Lords Baroness Smith of Basildon
Baroness Smith, along with Lords chief whip Lord Bassam, is set to boycott shadow cabinet meetings while Mr Corbyn remains in place, but will not resign because she was elected by her colleagues in the upper chamber.
The Labour MP for Basildon until 2010, Baroness Smith served as a Cabinet Office minister under Gordon Brown's government. She kept the position she had held since May 2015 under Mr Corbyn.
Lords chief whip Lord Bassam of Brighton
Like Baroness Smith, Lord Bassam, is not resigning his position because he was elected by colleagues in the upper chamber.
Former leader of Brighton and Hove City Council, he has held the chief whip position since May 2010.
Shadow minister without portfolio Jonathan Ashworth
The Leicester South MP was a shadow Cabinet Office minister under Ed Miliband. He backed Yvette Cooper in the leadership election over his Leicester neighbour Liz Kendall, telling the Leicester Mercury he had agonised over the decision.
New appointments to the shadow cabinet:
Shadow education secretary - Pat Glass, MP for North West Durham
Ms Glass, MP for North West Durham, was previously shadow minister for Europe and a shadow junior education minister.
She has a background in education and served as a member of the education select committee during the coalition government between 2010 and 2015.
She apologised during the UK's EU referendum after being recorded calling a voter a "horrible racist". She has now said she will step down as an MP at the next general election.
Shadow transport secretary - Andy McDonald, MP for Middlesbrough
Mr McDonald, an MP for Middlesbrough since 2012, was previously the shadow transport minister. He backed comments made my shadow home secretary Andy Burnham that there should not be a "civil war" in the Labour Party.
Shadow defence secretary - Clive Lewis, MP for Norwich South
Mr Lewis is one of several people new to the shadow cabinet who were elected in the 2015 general election. He is an opponent of Trident and wrote an article in the New Statesman about why Labour should oppose it. Mr Lewis is also a former reporter for the BBC and was BBC Look East's chief political correspondent.
Shadow chief secretary - Rebecca Long-Bailey, MP for Salford and Eccles
Ms Long-Bailey is also one of the 2015 general election intake. She tweeted a link to a petition calling for Jeremy Corbyn to remain leader, signed by more than 200,000 people, hours before she was appointed to the shadow cabinet. She had been serving as shadow treasury minister.
Shadow development secretary - Kate Osamor, MP for Edmonton
Ms Osamor was also elected in 2015. In January the then equality minister withdrew an advert for an unpaid intern, blaming a "misunderstanding" in her office. Ms Osamor has campaigned against low pay.
Shadow environment, food and rural affairs - Rachael Maskell, MP for York Central
Ms Maskell, who worked in the NHS before becoming an MP, was also one of those elected in 2015. She was previously head of health for Unite and has campaigned against changes to the NHS.
Shadow Northern Ireland secretary - Dave Anderson, MP for Blaydon
Mr Anderson was first elected to Parliament in 2005 and has a background in the trade union movement. A former coal miner and care worker, he is an honorary life member of the Unison union. He has an interest in Northern Ireland matters and up until last year served as a member of the Northern Ireland affairs committee.
Shadow voter engagement and youth affairs minister - Cat Smith, MP for Lancaster and Fleetwood
Ms Smith, who was elected in 2015 and was previously shadow minister for women, clashed with former Labour shadow chancellor Chris Leslie in January after he claimed the "hard left" was trying to take over the Labour Party following Mr Corbyn's reshuffle.
She said Mr Corbyn was "within his right" to choose who was in his top team and that he wanted to "realign" the shadow cabinet so it was a better match with the party.
Shadow energy secretary - Barry Gardiner, MP for Brent North
Mr Gardiner, an MP since 1997, has been promoted from shadow energy minister to replace Lisa Nandy as shadow energy secretary.
According to his website, Mr Gardiner had intended to seek ordination as a priest but his "sense of vocation changed" when Edinburgh Council sold off 718 houses, including his own.
Shadow justice secretary - Richard Burgon, MP for Leeds East
Mr Burgon, who was elected in 2015, has been promoted from the shadow Treasury team to become shadow justice secretary, replacing Lord Falconer. He had backed Mr Corbyn's leadership campaign and has publicly supported the Labour leader over his position on issues including the UK response to Syria.
Shadow women and equalities minister - Angela Rayner, MP for Ashton-under-Lyne
Mrs Rayner, who was elected in 2015 and was previously shadow work and pensions minister, takes over from Kate Green. She was previously a trade union official for Unison.
Shadow work and pensions secretary - Debbie Abrahams, MP for Oldham East and Saddleworth
Ms Abrahams, who was elected an MP in 2011 and was the former shadow minister for disabled people, replaces Owen Smith. Before becoming an MP she had resigned as chair of Rochdale Primary Care Trust in 2006 over reforms to the NHS.