A motion of no confidence in Labour leader Jeremy Corbyn has been passed by the party’s MPs.
The 172-40 vote, which is not binding, follows resignations from the shadow cabinet and calls on Mr Corbyn to quit.
Mr Corbyn said the ballot had “no constitutional legitimacy” and said he would not “betray” the members who voted for him by resigning.
The leader’s allies have told his critics to trigger a formal leadership contest if they want to challenge him. There were four abstentions in Labour’s secret ballot.
Labour’s leader in Scotland, Kezia Dugdale, suggested Mr Corbyn’s position was untenable, telling the BBC: “If I had lost the support of 80% of my MSPs I could not do my job.”
Labour MP and Corbyn critic Wes Streeting said the vote was “unprecedented”, adding: “I think Jeremy just has to accept now that his leadership is untenable.”
But following the result the leader issued a statement saying the government was “in disarray” following the vote to leave the EU, adding: “Labour has the responsibility to give a lead where the government will not.”
He added: “I was democratically elected leader of our party for a new kind of politics by 60% of Labour members and supporters, and I will not betray them by resigning. Today’s vote by MPs has no constitutional legitimacy.
“We are a democratic party, with a clear constitution. Our people need Labour Party members, trade unionists and MPs to unite behind my leadership at a critical time for our country.”
The most recent resignations from Mr Corbyn’s top team include shadow justice minister Andy Slaughter, and a senior figure in Labour local government is now calling for Mr Corbyn to go.
Dave Sparks, a councillor in Dudley and a former chair of the Local Government Association, warned that if Mr Corbyn stays, Labour will be wiped out.
He told the BBC that if the leadership does not change both its leader and its course, the party is looking at its support disappearing in England as it has melted away in Scotland.
Mr Corbyn faced calls to resign at a stormy meeting in the House of Commons on Monday after more than 20 members of his shadow cabinet and a similar number of junior ministers walked out, questioning his performance during the EU referendum and ability to lead the party.
Dame Margaret Hodge, the Labour MP who tabled the no confidence motion, said the Parliament Labour Party meeting had been “extraordinary”.
“I couldn’t believe the strength of feeling, the overwhelming rejection of Jeremy as our leader, and the pleading with him that he should consider his position and go with dignity,” she said.
But one of Mr Corbyn’s allies, newly promoted shadow health secretary Diane Abbott, said the no confidence vote “has no meaning”.
“MPs don’t choose the leader of the Labour Party, the party does,” she told Today.
“I think it is really sad that colleagues have chosen to stage this three-ring circus because they don’t want to have a leadership election because they are not certain of winning a leadership election.
“The way to resolve this is to have a leadership election.”
On Monday evening Mr Corbyn – who had also rebuked his party critics during a Commons speech – told grassroots supporters from the Momentum campaign group in a rally outside Parliament to stand up for the causes they believed in – including social justice, economic equality and human rights.
“Don’t let the media divide us; don’t let those people who wish us ill divide us,” he said. “Stay together, strong and united, for the kind of world we want to live in.”
Speaking at the same event, Mr McDonnell accused a “handful of MPs” of trying to “subvert” the party and challenged them to put up or shut up.
“The reason for this is that this is not about one individual. This is about the democracy of the (Labour) movement.”
Mr Corbyn’s deputy Tom Watson told him he had “no authority” among MPs and faced the prospect of a leadership challenge.
The talks between the two men were described as “civil” by a spokesman for the leader, but a senior Labour source said Mr Corbyn was left in no doubt he had lost the support of the Parliamentary Labour Party.
Several Labour MPs have cited the possibility of a general election in the next six months – following on from the election of a new Conservative leader – as the reason why Mr Corbyn must now consider his position.
And on Monday morning he announced a reshaped shadow cabinet to replace those that had walked out.
The shadow cabinet walkouts – in a bid to oust Mr Corbyn – came after the sacking at the weekend of shadow foreign secretary Hilary Benn, who told Mr Corbyn he had lost confidence in his leadership.
But Momentum, the campaign group that grew out of Mr Corbyn’s successful leadership bid, has said 4,000 people attended the rally outside Parliament, and Mr Corbyn has also been backed by the Unite, GMB and Unison trade unions. BBC