Dame Louise took to Twitter to make her shock announcement on Wednesday.

She wrote: “My decision has been truly agonising, as it has been for the thousands of other party members who have already left. I will not join any other party.

“I hope that under different leadership I will be able to return to my political home.

“I believe that Jeremy Corbyn is not fit to serve as our Prime Minster.

“With a looming General Election and the possibility of him becoming Prime Minister, I feel I have to take a stand. I cannot advocate a government led by Jeremy Corbyn.”

Dame Louise was under threat of deselection from her Liverpool Riverside Labour group, with a meeting scheduled to be held on Kol Nidrei — although this never took place.

The 73-year-old Manchester-born mother-of-one continued: “Under Jeremy Corbyn’s leadership, antisemitism has become mainstream in the Labour Party.

“Jewish members have been bullied, abused and driven out.

“Antisemites have felt comfortable and vile conspiracy theories have been propagated. A party that permits anti-Jewish racism to flourish cannot be called anti-racist.

“This is not compatible with the Labour Party’s values of equality, tolerance and respect for minorities.”

“The Labour Party is no longer a safe place for Jews and Jeremy Corbyn must bear the responsibility for this.”

Labour’s response was less than humble, however, citing its “robust” action in fighting antisemitism.

A spokesman said: “Jeremy Corbyn thanks Louise Ellman for her service to the Labour Party over many years.

“Jeremy Corbyn and the Labour Party are fully committed to the support, defence and celebration of the Jewish community and continue to take robust action to root out antisemitism in the party and wider society.”

Mike Katz, chairman of the Jewish Labour Movement, called it a “day of great shame for the party”, while Jewish Labour MP Dame Margaret Hodge said she was “absolutely devastated” by Dame Louise’s departure.

Joe Glasman, head of political and government investigations at Campaign Against Antisemitism, said: “Many of us have marvelled that Dame Louise has remained in the Labour Party for so long, even as it came under investigation by the Equality and Human Rights Commission at our behest.

“However, an imminent general election that raises the prospect of Jeremy Corbyn becoming Prime Minister has forced her to make the only moral choice possible, one which her colleagues still refuse to face.”

Solidarity was shown by many Labour MPs, such as Stella Creasy, who said that she was “ashamed” at the decision.

She added: “To be in a position where yet again another female Jewish MP feels no longer welcome in the Labour Party shames us all.”

But her decision to leave was lambasted by Lara McNeill, who sits as a youth representative on Labour’s National Executive Committee — the organisation which makes decisions on cases of antisemitism within the party.

Within minutes of Dame Louise’s announcement, Ms McNeill tweeted: “We are faced with an imminent election after a decade of Tory devastation.

“The choice is Johnson or Corbyn — and you choose to sit on the fence.

“Imagine writing that Jeremy Corbyn has spent decades ‘not confronting antisemitism and Holocaust deniers’ . . . demonstratively false.”

“Don’t ignore antisemitism, don’t ignore this Conservative government actively inciting racism and don’t ignore Labour’s — and Corbyn’s — record showing what a Labour government would actually mean for equality and anti-discrimination.”

She was immediately castigated by Luisa Attfield and Jack Lubner, the Jewish Labour Movement’s co-youth and student officers.

They told the PoliticsHome website: “For the second time, a Jewish MP has been bullied out of the Labour Party. This should be a great shame on us all.

“Instead of standing in solidarity with Dame Louise Ellman, Labour’s NEC Youth Rep accused her of ‘sitting on the fence’ and denying her lived experience of bullying and racism within the party.

“It is disgraceful behaviour from anyone, let alone a member of the party’s ruling body.

“If McNeill is not able to respond with empathy to a Jewish MP resigning as a result of antisemitism, she’s not fit to hold a representative role in the Party which requires being able to listen to the concerns of members.”

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