Britain’s Chief Rabbi has condemned the “poison” in the Labour Party that has been “sanctioned from the top” in an unprecedented election intervention.

In an article for The Times newspaper, Ephraim Mirvis said that a general election victory for Labour will put the “very soul of our nation” at stake, and said that ahead of the December 12 poll “the overwhelming majority of British Jews are gripped by anxiety”.

He criticised Jeremy Corbyn for being “complicit in prejudice” and “unfit for office”.

The Labour leadership and the party’s structures have been accused of failing to tackle complaints of anti-Semitism quickly enough since Corbyn took charge and several MPs have quit the party over the issue.

Mirvis said people of the Jewish faith have expressed “justified” concern about anti-Semitism in the Labour Party.

He said: “Of course, the threats of the far-right and violent jihadism never go away, but the question I am most frequently asked is, ‘What will become of Jews and Judaism in Britain if the Labour Party forms the next government?’

“Raising concerns about anti-Jewish racism in the context of a general election ranks among the most painful moments I have experienced since taking office.”

The Chief Rabbi criticised Corbyn for an “utterly inadequate” response to anti-Semitism within Labour.

He concluded: “I simply pose the question: What will the result of this election say about the moral compass of our country?

“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.”

A Labour spokesman said: “Jeremy Corbyn is a lifelong campaigner against anti-Semitism and has made absolutely clear it has no place in our party and society and that no-one who engages in it does so in his name.

“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. Our race and faith manifesto sets out our policies to achieve this.”

Rabbi Julia Neuberger, a crossbench peer, told BBC Radio 4′s Today programme this morning that Jewish people would feel “oppressive, uncomfortable, dangerous” if Corbyn becomes PM.

But Labour peer Lord Dubs, who arrived in the UK in 1939 as a six-year-old refugee fleeing the persecution of Jews in Nazi-occupied Czechoslovakia, said the Chief Rabbi had “gone too far”.

“I think Jeremy Corbyn himself is personally hurt at the accusations of anti-Semitism,” he told the BBC.

“I don’t believe he is anti-Semitic, even though, under his leadership, things have happened which should have been dealt with much faster.”

On Tuesday morning, the Archbishop of Canterbury, Justin Welby, said that the fact 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”.

Labour is under investigation by the Equality and Human Rights Commission (EHRC) for allegedly allowing prejudice against Jewish people to flourish among some members of the party.

Corbyn will launch his party’s race and faith manifesto in Tottenham, north London, on Tuesday with pledges to improve social justice and human rights.

In it, the party says it wants to make the EHRC “truly independent”. A spokesperson for the Jewish Labour Movement said: “We’re so through the looking-glass when Labour says it will create a ‘truly independent’ EHRC.”

Earlier this year, several then-Labour MPs including Luciana Berger and Chuka Umunna defected to the Liberal Democrats because of Corbyn’s handling of anti-Semitism and Brexit.

On Monday night, Berger spoke in support of the Chief Rabbi’s “unprecedented” plea for the British public not to vote Labour.

Berger, who quit Labour in February over the party’s alleged anti-Semitic prejudice, said on Twitter: “Unprecedented and devastating intervention from the Chief Rabbi.

“During the the last meeting I had with @jeremycorbyn at the end of 2017 I told him about the many public and private Facebook groups that were littered with antisemitic posts which used the Labour leader’s name/and photo in their group name.

“Nothing was done about it following our meeting.

“Tonight the party says ‘that no one who engages in it (antisemitism) does so in his (Jeremy Corbyn’s) name.’ But that is exactly what has happened.”