LONDON — It’s not just Britain’s ruling Conservative Party that is in turmoil after the nation voted last week to quit the European Union. The opposition Labour Party is restive, too, with festering criticism of its leader, Jeremy Corbyn, coming to the surface.
Early Sunday, Mr. Corbyn abruptly fired his shadow foreign secretary — the party’s spokesman on foreign affairs — to try to head off an internal coup begun by some Labour members of Parliament disappointed with Mr. Corbyn’s lackluster campaign to keep Britain in the bloc.
The shadow foreign secretary, Hilary Benn, telephoned Mr. Corbyn to say that he and other key legislators had lost confidence in Mr. Corbyn to lead the party to victory in the next election, which could be later this year. Mr. Corbyn ended the call by firing him, Mr. Benn told the British news agency The Press Association on Sunday.
“Following the result of the E.U. referendum, we need strong and effective leadership of the Labour Party that is capable of winning public support,” Mr. Benn said. “In a phone call to Jeremy I told him I had lost confidence in his ability to lead the party and he dismissed me.”
Later Sunday morning, Heidi Alexander, who speaks for the party on health issues, stepped down. Up to half the shadow cabinet is considering resignation, according to the BBC. Mr. Corbyn faces a vote of confidence, which was called for on Friday, after the referendum, by two lower-ranking Labour legislators.
Mr. Corbyn and his allies are reported to be organizing demonstrations in his support. On Sunday morning, his office issued a terse statement: “There will be no resignation of a democratically elected leader with a strong mandate from the membership.”
In its Sunday editions, The Observer reported that Mr. Benn was trying to organize a serious move to unseat Mr. Corbyn because the political landscape had changed with the referendum vote and the resignation of Prime Minister David Cameron.
A new Conservative leader, elected by the party, would become prime minister in the fall and would probably try to call a general election to secure a new mandate. In the view of Mr. Benn and numerous other Labour legislators who oppose their leader, Mr. Corbyn would lead Labour to a disastrous defeat.
Mr. Corbyn became leader after Labour’s loss to Mr. Cameron in the May 2015 general election and the resignation of Ed Miliband. A man of the hard left, Mr. Corbyn was opposed by the parliamentary party as he rose. Still, he was elected under new party rules that said anyone could register to vote by paying 3 pounds, whether that person was a member of the Labour Party or not.
Mr. Benn has been an internal critic of Mr. Corbyn and nearly lost his job in December, when he supported authorizing airstrikes against the Islamic State in Syria, a move that Mr. Corbyn opposed. In the end, Mr. Corbyn agreed to let Labour legislators vote their conscience on the matter and allowed Mr. Benn to speak in favor of the motion in Parliament.
The call for a motion of no confidence in Mr. Corbyn is a demand to discuss the issue at the next meeting of Labour legislators, scheduled for Monday. The chairman will decide whether it is debated. If accepted, a secret ballot of Labour legislators could be held on Tuesday.