Rabbi Ephraim Mirvis, Britain’s chief rabbi, arrives to attend the National Service of Remembrance, on Remembrance Sunday, at The Cenotaph in Westminster, London, Nov. 10, 2019. Photo: Reuters / Simon Dawson.

Britain’s chief rabbi said opposition Labour leader Jeremy Corbyn was unfit to be prime minister because he had failed to stem antisemitism “sanctioned from the top” and now gripping his party.

His comments stirred up campaigning ahead of the Dec. 12 vote where the United Kingdom faces a stark choice between Prime Minister Boris Johnson offering Brexit and Corbyn proposing a radical socialist vision for the world’s fifth-largest economy.

Chief Rabbi Ephraim Mirvis, in an article in The Times, questioned how complicit in prejudice an opposition leader would have to be to be considered unfit for office.

“It is a failure of leadership. A new poison — sanctioned from the top — has taken root in the Labour Party,” wrote Mirvis, of the United Hebrew Congregations of the Commonwealth.

“Be in no doubt, the very soul of our nation is at stake.”

Such an intervention from a religious leader is unusual.

Anglican leader Justin Welby said it was unprecedented and indicated the fear felt by many Jews.

Ever since Corbyn became Labour leader in 2015, he has been dogged by criticism from members, lawmakers and Jewish leaders that he has failed to tackle antisemitism in the party.

Nine lawmakers quit Labour in February, citing its leadership’s handling of the accusations among their reasons, and in May Britain’s equality watchdog launched an investigation into possible discrimination by the party.

Mirvis said Labour leaders’ response as their supporters drove lawmakers, members and staff out of the party for challenging anti-Jewish racism had been “utterly inadequate.”

Corbyn has also been criticized for the party’s delay in fully adopting the International Holocaust Remembrance Alliance’s definition of antisemitism.

A Labour spokesman claimed Corbyn was a lifelong campaigner against antisemitism and the party was rooting out discrimination with suspensions and education programs.

“A Labour government will guarantee the security of the Jewish community, defend and support the Jewish way of life, and combat rising antisemitism in our country and across Europe,” the spokesman said.

With just over two weeks until the election, a poll by Kantar showed Labour had squeezed the Conservative lead to 11 points from 18 over the last week.