Jeremy Corbyn is facing an open revolt within his party as a series of shadow cabinet members quit in protest at his leadership.
They are Heidi Alexander, Ian Murray, Gloria de Piero, Lillian Greenwood, Lucy Powell, Kerry McCarthy, Vernon Coaker, Lord Falconer and Seema Malhotra.
Mr Corbyn sacked shadow foreign secretary Hilary Benn overnight.
The Labour Party campaigned for Remain during the referendum, which saw the UK voting to leave the EU by 52% to 48% on Thursday .
But Mr Corbyn was criticised for not making the case for the EU forcefully enough.
Ms Powell resigned as shadow education secretary and told Mr Corbyn his position is “untenable”. She said he could not command the support of Labour MPs or the country.
Shadow transport secretary Ms Greenwood is also understood to have resigned. Heidi Alexander was shadow health secretary, Gloria De Piero was shadow minister for young people and Ian Murray was shadow Scottish secretary. Kerry McCarthy was shadow environment secretary and Seema Malhotra was shadow chief secretary to the Treasury.
The Press Association says Labour sources have indicated that shadow Commons leader Chris Bryant and shadow environment secretary Kerry McCarthy are among a group of at least 10 members of Mr Corbyn’s top team also expected to quit.
Hilary Benn was sacked amid reports that he was working to co-ordinate a coup against Mr Corbyn.
Hilary Benn arrives back at his home in London after appearing on The Andrew Marr Show on Sunday
But shadow home secretary Andy Burnham said he would remain in Mr Corbyn’s top team.
He said: “At an uncertain time like this for our country, I cannot see how it makes sense for the Opposition to plunge itself into a civil war.”
Ms Powell used her resignation letter to Mr Corbyn to warn that the party faced an “existential threat” and told him that he did not understand the concerns of voters in the Labour heartlands.
Aberavon Labour MP Stephen Kinnock has been making the case for Jeremy Corbyn to step down.
He told the BBC: “The next three, five, 10 years are going to be totally about Brexit negotiation. We need a cross-party approach. We need a negotiating team where the leader of the opposition plays a key role.
“That means the leader of the opposition has to be a negotiator, somebody that can really roll up his or her sleeves and work to secure the best possible deal for the British people. Whilst I have a huge amount of respect for Jeremy as a politician he is not a negotiator.
“I don’t think he has the set of skills or experience that we need for a new reality.”
Many of the thousands of people who pushed Mr Corbyn to his thumping victory in last year’s four-way leadership race will bristle at the thought of him being dispatched.
But Mr Kinnock argued: “What I think is very important is the membership understand we’re going to have a general election before the end of this year. The new Tory leader will have to seek a fresh mandate. And the mandate for the leader pre-referendum is completely different…
“The job description has changed. We need a different kind of skills and experience.”
Carwyn on Corbyn
Earlier in the day, First Minister Carwyn Jones was asked whether he thought Jeremy Corbyn could lead the Labour party into a general election in the near future.
Mr Jones said: “Well, clearly it makes it very difficult because if half the shadow cabinet team resign then clearly there is a division in the shadow cabinet that would need to be healed.”