Labour Party leader Jeremy Corbyn’s election campaign was hit Thursday by renewed claims that he is not fit to lead the country because of his tolerance of anti-Semitic attitudes.

The criticism came from a former member of the Labour Party’s inner circle who took the extraordinary step of urging British voters to instead elect Conservative Prime Minister Boris Johnson — Corbyn’s main rival — and from an influential Jewish newspaper that urged Britons not to back Corbyn in the country’s Dec. 12 general election.

Ian Austin, a close aide to the Labour Party’s last prime minister, told the BBC the left-wing party has been poisoned by “anti-Jewish racism” under Corbyn. Austin was one of seven lawmakers who left the Labour Party in February because of anti-Semitism and its convoluted Brexit policy.

He said “decent, traditional patriotic Labour voters” should vote for Johnson and the Conservatives rather than let Corbyn take power. He said the “scandal of anti-Semitism” has poisoned Labour since Corbyn was elected party leader in 2015.

Over his long political career, the 70-year-old Corbyn has championed the grievances of groups such as the Irish Republican Army, Hamas and Hezbollah.

Corbyn has been accused of failing to expel party members who express anti-Semitic views and has received personal criticism for past statements, including a 2010 speech in which he compared Israel’s blockade of Gaza to Nazi Germany’s sieges of Leningrad and Stalingrad during World War II.

Critics have also condemned him for attending a 2014 wreath-laying ceremony honoring Palestinians whom Israel has linked to the murders of 11 Israelis at the 1972 Munich Olympics.

These concerns were echoed Thursday by the Jewish Chronicle weekly newspaper, a fixture in Britain’s Jewish community since 1841. It took the unusual step of publishing a front-page editorial aimed at “non-Jews” who would not normally read the paper.

The newspaper said its polling indicated that 47% of Britain’s Jews would “seriously consider” leaving the country if Corbyn becomes prime minister. The editorial said those fears were raised when Corbyn became party leader but that some had hoped he would become more tolerant.

“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,” the newspaper said.

It urged voters who abhor racism to consider Corbyn’s views when they make their choice on Dec. 12.

Labour’s fledgling campaign has also been rocked by the resignation of deputy leader Tom Watson on Wednesday night.

The comments by Austin and Watson’s resignation underscore the unease that many Labour lawmakers have with Corbyn’s left-wing views, his leadership and his reluctance to take a clear stand on whether Britain should leave the European Union or remain in the 28-nation bloc.

Corbyn has moved Labour further to the left and away from the center ground staked out by former Prime Minister Tony Blair, who led the party to three straight election triumphs.

The reaction from Labour leaders was swift.

“Voting for Boris Johnson if you are a Labour voter and you want to protect your community is absolutely absurd and it makes no sense at all,” said Rebecca Long-Bailey, Labour’s business spokeswoman.

John McDonnell, Labour’s economy spokesman and a key Corbyn ally, said Labour was “saddened” by criticism in the Jewish media but added “we’re doing everything they asked of us to address this issue.”

All 650 seats in the House of Commons are up for grabs in the Dec. 12 election, chosen by 46 million voters.

Johnson pushed hard for the vote, which is coming more than two years early, after Parliament thwarted his plans to have Britain leave the EU on Oct. 31. Johnson hopes to win an outright majority in Parliament so he can pass a divorce bill in time for Britain to leave by the next Brexit deadline on Jan. 31.

Up until now, Brexit has been the main issue of the campaign, but Labour is trying to shift the debate onto domestic issues such as health care, the environment and social welfare.

Conservatives are leading in the polls, but the election is complicated because the issue of Brexit divides the country and cuts across party lines.

John Bercow, the former House of Commons speaker who oversaw Britain’s bruising parliamentary battles over Brexit, told The Associated Press in an interview Thursday that leaving the EU would be a historic mistake but added it’s not too late to reverse the decision.

In his previous job Bercow had to be neutral, but he now says Brexit is the country’s “biggest foreign policy blunder” since World War II, an error that will leave Britain weakened economically and diplomatically.

“We’re in a world of power blocs and of trade blocs,” Bercow said. “And it makes more sense for the U.K. to be part of that power bloc called the European Union.”

Other parties competing in the Dec. 12 election include the Liberal Democrats, who want to cancel Brexit; the Scottish National Party, which opposes Brexit and wants Scotland to leave the U.K.; and the Brexit Party, which says Britain should leave the bloc without a deal.

(AP)