The poison of anti-Semitism "sanctioned from the top" has taken root in Britain's opposition Labor Party, Chief Rabbi Ephraim Mirvis said in an article published on Monday, warning the "soul of our nation is at stake" in next month's election.
Labor leader Jeremy Corbyn, a veteran campaigner for Palestinian rights, has been dogged by criticism from members, lawmakers and Jewish leaders that he has failed to tackle anti-Semitism in the party despite a promise to do so.
"The question I am now most frequently asked is: What will become of Jews and Judaism in Britain if the Labor Party forms the next government? This anxiety is justified," Mirvis, Chief Rabbi of the United Hebrew Congregations of the Commonwealth, wrote in an article for Tuesday's edition of the Times newspaper, entitled "What will become of Jews in Britain if Labour forms the next government?"
He said the response of the party's leadership as their supporters drove lawmakers, members and staff out of the party for challenging anti-Jewish racism had been "utterly inadequate" and claims the party was doing everything it could and had investigated every case were "mendacious fiction."
"It is a failure to see this as a human problem rather than a political one. It is a failure of culture. It is a failure of leadership.
"A new poison sanctioned from the top has taken root in the Labor Party," he wrote.
Mirvis won apparent support Tuesday from the leader of the Church of England, Archbishop of Canterbury Justin Welby, who wrote on Twitter: "That the Chief Rabbi should be compelled to make such an unprecedented statement at this time ought to alert us to the deep sense of insecurity and fear felt by many British Jews".
A spokesman for Labour, who are trailing Prime Minister Boris Johnson's Conservatives in the polls ahead of the Dec. 12 election, said Corbyn was a lifelong campaigner against anti-Semitism - a claim dismissed by members of the British Jewish community who point to his embrace of known anti-Semites and Holocaust deniers.
"A Labour government will guarantee the security of the Jewish community, defend and support the Jewish way of life, and combat rising anti-Semitism in our country and across Europe," the Labour spokesman said.
Earlier this year, more than 60 Labour members of Britain's House of Lords signed a statement in a newspaper accusing Corbyn of failing "the test of leadership" over anti-Semitism in the party.
Eight lawmakers have left the party this year over anti-Semitism and Corbyn's position on Brexit. Among them was Jewish MP Luciana Berger, who said she could not remain a member of a party that was “institutionally anti-Semitic.”
She accused the Labour leadership of failing to address hatred directed at the party's Jewish members.
"I am leaving behind a culture of bullying, bigotry and intimidation," she said.
Mirvis said Tuesday that while convention dictates that the chief rabbi stays away from party politics, challenging racism went beyond politics.
"How complicit in prejudice would a leader of Her Majesty's opposition have to be to be considered unfit for office? Would associations with those who have incited hatred against Jews be enough? Would describing as 'friends' those who endorse the murder of Jews be enough? It seems not," he said.
"When December 12 arrives, I ask every person to vote with their conscience. Be in no doubt, the very soul of our nation is at stake."
Corbyn, a self-styled peace campaigner, has been accused by numerous lawmakers for failing to tackle anti-Semitism in the party, an allegation that has dogged the pro-Palestinian politician since he became leader in 2015.
The Labour leader, whose anti-Israel stance is no secret, last year denied visiting the graves of the terrorists behind the massacre of 11 Israeli athletes at the 1972 Munich Massacre, but photos published by the Daily Mail days later showed him at a 2014 memorial service in Tunisia for members of the Black September terror organization that carried out the murders.
In photos taken a year before Corbyn was elected as the leader of the Labour Party, he is seen holding a wreath over the grave of Atef Bseiso, the head of intelligence for the Palestine Liberation Organization (PLO), who helped plan the attack at the Munich Olympics.
AP and Ynet correspondents contributed to this report