Labour MPs seeking to overthrow Jeremy Corbyn must accept his leadership if he sees off the challenge, John McDonnell said as he called for an end to “nastiness”.
A defiant Mr Corbyn has vowed to fight on despite an overwhelming vote of no confidence by his own MPs, who declared their wish to see him gone by a margin of more than four to one.
Angela Eagle – the most senior member of the shadow cabinet to join a mass mutiny that has left Mr Corbyn struggling to find sufficient loyal members to form a new team – is widely tipped to be chosen to take him on in a formal contest.
But while his Westminster colleagues are lined up against him, the leadership appears confident he still commands sufficient support among the wider membership to emerge victorious once again.
Crucially, he also appears to enjoy the support of trade union chiefs.
Mr Corbyn shocked the party when he battered established mainstream rivals in September on the back of an influx of left-wing activists, who have kept up a vocal support through the Momentum group.
Former foreign secretary Margaret Beckett warned there were “people around Jeremy who are prepared to see the Labour Party split rather than for him to go”.
“That is anathema to everybody who thinks that we need to get rid of this Government and the damage that they are doing,” she told BBC Radio 4’s Today in an emotional appeal to the leader to step aside.
Dame Tessa Jowell told him it was “absolutely clear that your continued leadership is putting the Labour Party’s future in jeopardy and denying millions of people in our country who so desperately need representation by a Labour government”.
But Mr McDonnell said MPs had to “play by the rules”.
“It looks as though we will have a leadership election,” he conceded.
“All we are saying to Labour MPs is: play by the rules of our party and, if there is to be a democratic election, respect the decisions of our members.”
He told Sky News: “The most important thing at the moment is just calm down.
“Our country is facing some really serious risks at the moment and we have a job as MPs to try to come together to protect the people who might be affected, and they are largely the most vulnerable.
“We are all saddened that we are going through this because it is completely unnecessary and there has been some nastiness.”
Mr Corbyn dismissed the confidence vote as having “no constitutional legitimacy” and insisted he would not “betray” the 60% of members and supporters who backed him to succeed Ed Miliband.
He will address a rally organised by the Momentum movement on Wednesday evening, with Public and Commercial Services union chief Mark Serwotka and Fire Brigades Union general secretary Matt Wrack also speaking in support of him.
Unite trade union general secretary Len McCluskey was among the first to rally to Mr Corbyn’s support after the no-confidence motion, accusing the MPs of “pointless posturing” and warning they would have to mount a full-blown leadership challenge if they wanted to oust him.
