LONDON — Nobody expected Britain’s general election to follow a smooth script, and by the end of a second hectic day of campaigning both of the country’s major parties had suffered a series of unexpected bumps and blows. On Thursday, it was the opposition Labour Party’s turn.
Two former Labour members of Parliament declared that they planned to vote for the Conservative Party because they said Labour’s leader, Jeremy Corbyn, was unfit to be prime minister. Their comments came a day after the sudden resignation of the party’s deputy leader, Tom Watson, who had tangled for years with Mr. Corbyn over Brexit policy and anti-Semitism in the party’s upper ranks.
The upheaval threw Labour’s campaign into disarray only a day after Prime Minister Boris Johnson’s Conservatives stumbled out of the gate. In just 24 hours they were hit with the sudden resignation of one of Mr. Johnson’s cabinet ministers in a legal scandal, an apology from another following widely condemned comments about the Grenfell Tower fire and accusations that the party had doctored a TV interview with a prominent Labour politician.
In Labour’s case, the internal dissent resurfaced allegations of anti-Semitism that have long haunted the party.
“I can’t really believe it’s come to this, but I think I need to tell people that Jeremy Corbyn isn’t fit to lead the Labour Party,” Ian Austin, who had been an adviser to former Prime Minister Gordon Brown, said in an emotional interview broadcast on Sky News. “He’s certainly not fit to lead the country.”
Mr. Austin, who left the party earlier this year, accused Mr. Corbyn of having sided with Britain’s enemies, whether it be the Irish Republican Army in Northern Ireland or Hamas and Hezbollah in the Middle East. The adopted son of a Czech-Jewish father who fled the Nazis, Mr. Austin said Mr. Corbyn had allowed a culture of extremism and anti-Semitism to fester in the Labour Party.
He was joined by another former Labour lawmaker, John Woodcock, who also said he would vote for Mr. Johnson.
Their rebellion coincided with a front-page article in an influential London-based Jewish newspaper, the Jewish Chronicle, which urged non-Jews to vote against the Labour Party because of what the editors said was Mr. Corbyn’s long record of espousing and tolerating anti-Semitic views.
“There were some who hoped that he might change as leader,” the paper said. “The opposite has happened. The near total inaction of Mr. Corbyn and the rest of the Labour leadership in dealing with anti-Semites in the party has both emboldened them and encouraged others.”
Mr. Corbyn, a strong critic of Israel, has long denied being an anti-Semite. He said the Labour Party had investigated the allegations and suspended or expelled members found guilty of anti-Jewish statements. He did not address the latest charges, which dominated news coverage on a day when he had hoped to sharpen Labour’s attack on Mr. Johnson’s Conservatives for their policy of a swift exit from the European Union.
Mr. Watson’s resignation revealed other tensions in the party, which have deepened since Mr. Corbyn became leader in 2015. As deputy leader, he had been the most senior of Mr. Corbyn’s critics to survive with a leadership role in the party and had used that position to promote a conspicuously different agenda.
An outspoken opponent of Brexit, Mr. Watson pressed first to embrace the policy of holding a second referendum and then, unsuccessfully, sought to make Labour commit to remaining in the European Union.
Mr. Corbyn, a lifelong Euroskeptic, resisted that, insisting that Labour should stick to a policy of negotiating a new Brexit deal, then putting that to a referendum with the alternative option of remaining in the bloc.
Mr. Watson was also vocal in his criticism of the party’s failure to deal with allegations of anti-Semitism. He expressed alarm when another Labour lawmaker, Luciana Berger, quit, saying she had been driven out of the party. It was, he said, the “worst day of shame” in the party’s history.
After Ms. Berger and a handful of other lawmakers left the party this year to protest Mr. Corbyn’s leadership, Mr. Watson formed a new caucus for social democrats and urged the centrists to stay and fight.
However, he now becomes the latest moderate lawmaker to quit Parliament, among them Owen Smith, who challenged Mr. Corbyn for the leadership in 2016 — an exodus that is noticeable in the Conservative Party as well and that analysts say is radicalizing both of them.
For Mr. Corbyn’s most ardent supporters, Mr. Watson had become a reviled figure. On the eve of the Labour Party’s annual conference in September, allies of Mr. Corbyn tried unsuccessfully to abolish his job. He also came under fire for raising accusations that prominent British establishment figures had sexually abused boys — claims made by a man whose evidence subsequently proved to be false.
In his resignation letter, Mr. Watson promised to continue to fight for Labour. Unlike Mr. Austin and Mr. Woodcock, he said he would support the party’s candidates in the general election.