Jeremy Corbyn has asked Britain’s chief rabbi Ephraim Mirvis to “engage” with him after the Labour leader was accused of sanctioning the “poison” of racism against Jewish people.

In an unusual intervention in party politics on Tuesday, Mirvis said Labour’s handling of anti-Semitism – accusations around which have dogged the party under Corbyn’s leadership – was “incompatible” with British values.

Speaking at the launch of Labour’s race and faith manifesto in north London on Tuesday afternoon, Corbyn said there was “no place whatsoever for anti-Semitism in our society, our country, or in my party”.

He added: “Be absolutely clear of this assurance from me – no community will be at risk because of their identity, their faith, their ethnicity or their language.”

Corbyn said: “I ask those that think things have not been done correctly to tell me about it, to talk to me about it, but above all engage. I am very happy to engage with anybody. My whole life has been engaging with people.”

Boris Johnson said the chief rabbi’s comments were a “very serious business”.

“I’ve never heard anything like it and clearly it is a failure of leadership on the part of the Labour leader that he has not been able to stamp out this virus in the Labour Party,” the prime minister said during a visit to Scotland.

Writing in The Times, Mirvis said the overwhelming majority of Britain’s Jews were “gripped with anxiety” ahead of the general election on December 12, warning “the very soul of our nation is at stake”.

Mirvis said “a new poison – sanctioned from the top” had taken root in the Labour Party.

He added: “How complicit in prejudice would a leader of Her Majesty’s Opposition have to be to be considered unfit for office?”

Mirvis received high-profile backing from the Archbishop of Canterbury, Justin Welby, who said his intervention reflected the alarm felt by many in the Jewish community.

“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,” he said.

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 he was “bitterly disappointed” at what Mirvis had said.

“I think today of all days for the chief rabbi to be attacking the Labour Party in this particular way and attacking our leader is unjustified and unfair, and I am bitterly, bitterly disappointed that he’s done that,” he added.

Labour’s race and faith manifesto includes a commitment to make the Equality and Human Rights Commission, which is currently investigating Labour anti-Semitism, “truly independent”.