The political upheaval in Britain caused by its vote to leave the European Union has shifted to the Labour Party, with leader Jeremy Corbyn refusing to step down despite a growing revolt that some say could destroy the 116-year-old party.
"Jeremy is staying leader of the Labour Party," John McDonnell, a senior party MP, told reporters on Friday. "If there's a leadership challenge, I think he'll win."
Dissent within Labour has been building since last week's referendum and dozens of MPs have called for Mr. Corbyn to quit. In recent days, more than 60 MPs have resigned their front-bench positions in protest of his leadership and 172 of the party's 229 MPs backed a vote of non-confidence in Mr. Corbyn.
Mr. Corbyn, who was elected leader last year, has insisted he has a mandate from the party membership, and groups of activists have held rallies outside parliament on his behalf. "I was elected leader of our party, for a new kind of politics, by 60 per cent of Labour members and supporters. The need for that different approach now is greater than ever," he said. After his election, however, he proved more divisive than uniting of the Labour Party. More recently, he has come under fire for what many saw as a lacklustre effort for the Remain side in the referendum campaign.
The scale of the revolt has been unprecedented and unexpected. For weeks leading up to the referendum vote, it was the ruling Conservatives who were divided over the EU. Prime Minister David Cameron, who backed remaining in the EU, was pitted against fellow cabinet minister Michael Gove and Tory MP Boris Johnson, who campaigned for Vote Leave.
With the country voting to leave, Mr. Cameron has announced plans to step down. That kicked off a leadership contest that will see a new prime minister in place by Sept. 9. On Friday, Mr. Gove fleshed out his campaign for leader, promising to cut immigration and boost health-care spending. Mr. Gove's surprise entry into the race thwarted Mr. Johnson, who was considered a favourite but pulled out. Now Mr. Gove and Home Secretary Theresa May are the front-runners.
While the Tory race has been divisive, it pales in comparison to the Labour strife.
Labour went into the referendum campaign far more united with all but 10 MPs backing the Remain side. There was even hope among some Labour MPs that the party could take advantage of the Tory infighting. "I think there will be a big space for us to step into [after the referendum] because the Tories will be all over the shop," Stephen Kinnock, a Labour MP, said in an interview days before the vote.
But as soon as the first results came in, Labour's problems emerged. Party strongholds in Sunderland, Birmingham, Wigan, Swansea, Stoke and Doncaster supported Vote Leave, despite active campaigning by Labour MPs.
It was clear that Labour had lost touch with its base, which now seemed more aligned with the United Kingdom Independence Party and its message of immigration control.
Many MPs blamed Mr. Corbyn, who looked disinterested in the referendum campaign and has never been committed to the EU. Others worried about the party's fate if the new Tory Prime Minister called a snap election this fall.
But getting rid of Mr. Corbyn is proving tricky. No sitting Labour leader has ever been deposed and it's not even clear how Mr. Corbyn can be pushed out. Under party rules, a challenger to the leader must be nominated by 51 of the party's MPs and Members of the European Parliament. The party's general secretary could then call a leadership vote among party members.
A couple of MPs have begun rounding up the required support, but they are waiting for the national executive to decide whether Mr. Corbyn would also need to be nominated by 51 MPs and MEPs in order to run in that contest. Given his unpopularity in caucus, the dissidents believe he would find that impossible and he would have to resign. However, if the executive determines that Mr. Cobryn does not have to be nominated because he is the sitting leader, many believe he still has enough support among party members to win a leadership vote.
"I think we end up with … a very, very acrimonious formal split of the party," said Robert Ford, a professor of political science at the University of Manchester. "I think everyone is aware that the stakes are so high, which is why they don't want to cross the Rubicon on this issue of a formal challenge if they can find some way getting the guy to [resign]. If he doesn't, then the risk is disaster."
Prof. Ford said Labour is wrestling with the difference between many party members, who tend to be young social activists who back Mr. Corbyn, and traditional Labour voters. The referendum result, he said, has "scared the crap out of a lot of MPs who haven't really been worried about their job security ever before."