Labour MP John Mann has tonight announced he will resign from Parliament in protest at Jeremy Corbyn's failure to tackle rampant antisemitism within the party.
Mr Mann - MP for Bassetlaw since 2001 - has opted take up a new full-time role as the government's antisemitism tsar.
Speaking to the JC about the decision, made only weeks before a likely General Election, he confirmed: "I'm not prepared to stand as an MP with Corbyn as leader."
He said he had written to Mr Corbyn explaining his decision to stand down and in a hard-hitting letter repeated his call for the Labour leader to resign.
"I have told him to resign for the good of the country and for the good of the Labour Party," he said.
The 59-year-old politician, whose constituency had a 5,000 Labour majority in 2017, said there was a problem with antisemitism in other political parties but that Mr Corbyn's failure to tackle it within Labour had left "huge consequences".
He said: "When Corbyn goes the problem doesn't go with Corbyn.
"But his failure to lead is the big problem - as is the problem of antisemitism on the left.
"Corbyn is an enabler. His unwillingness to undo the damage he has done has had huge consequences.
"He's not just an enabler - he's the enabler in this country.
"His refusal to sort things out - and the things he's done and said in the past - gives an open licence to it."
Mr Mann hit out at suggestions his decision to stand down and take up the new role was deliberately timed to raise the issue of antisemitism again with a general election on the cards.
He revealed he had witnessed open antisemitism as recently as last Thursday as he joined Community Security Trust chief executive David Delew and his wife at an outside table at Reubens kosher restaurant in London.
"It was after the CST's advisory board meeting. I joined Mr and Mrs Delew for a conversation when we were subjected to casual but explicitly antisemitic abuse from four people passing by.
"It was 'Jew this...Jew that' to two members of the community and myself who were just sitting outside having some food and attempting to chat.
"That's the scale of the problem - it's becoming normalised."
Mr Mann said the growth in antisemitic activity has "without question been running in tandem with Corbyn's lack of leadership."
Mr Mann said that there were also serious issues with antisemitism from the far-right and within the Muslim community.
"There is a big problem," he said of the later issue. "And I have never been one to shy away from dealing with difficult issues."
The outspoken MP stressed that the new role, which was given the go-ahead by Theresa May in one of her last acts as Prime Minister, would allow him to devote his full attention to issue of anti-Jewish racism in the UK and abroad.
"I'm not retiring, far from it," he said.
"The role will allow me to devote 95 per cent of my life to fighting the war against antisemitism, rather than the five per cent I was able to devote while working as an MP."
He added that the new job will see him working independently of any political party.
As the former chair of the All Party Parliamentary Group Against Antisemitism, Mr Mann had been given stark insights into the scale of the Jew-hate problem in recent years.
"I've dealt with problems in the Conservative Party - brutally in the past," he said.
"They've been smart enough to sort them out. They've got rid of people.
"If there are antisemites in the Tory Party, I'll be as robust with Boris Johnson and James Cleverly as I have been with Labour in the past. If they are smart enough they will sort it out.
"On occasions I will say that if they sort the problem out, then I won't embarrass them, I won't publicise it.
"Deal with it ruthlessly and efficiently - that has happened. I think that's a good system.
"Labour has chosen not to do that. More fool them.
"But there's problems in other parties as well."
His first engagement as government antisemitism tsar is on September 24 at an Organisation for Security and Co-operation in Europe (OSCE) conference in Warsaw, Poland where he will share a platform with the German envoy on antisemitism, Felix Klein, and Donald Trump's adviser on the same issue, Elan Carr.
"I think I can make a significant impact internationally, particularly on ares such as the IHRA definition," Mr Mann said.
Days later, Mr Mann will make a keynote address at Kinloss synagogue in north London and he said it is his "intention to get around the Jewish community."
He added: "My immediate priority is carrying out a series of interviews with Jewish teenagers. I want to hear their view on life in Britain and how they see their futures here."
Mr Mann revealed he would not be resigning his Labour membership - despite his hatred of the current leadership.
He insisted: "It's my party. I want to see Corbyn resign from the leadership. And I want all the antisemites out. But I'm not resigning. Absolutely not.
"I will carry on this fight from within."
Mr Mann also praised Labour MPs such as Dame Louise Ellman, Ruth Smeeth and Wes Streeting, who he said were speaking out over antisemitism.
And he criticised suggestions these MPs were themselves at fault for failing to stand up more against their leader.
"Some people are spending too much time criticising people who are in the front line. Attacking people like the Ruth Smeeths of this world is both inappropriate and sad and tactically stupid.
"The people you should be attacking are clearly the antisemites and also those who are still silent on the issue.
"I commend the bravery of Louise, Ruth, Wes and the other MPs who have bravely stood up - some of them have had real hassle for doing so."
He also rejected suggestions that the pro-Brexit movement, of which he is a supporter, had itself contributed to a rise in antisemitism across society.
"The Livingstone incident [when Mr Mann confronted the former London Mayor over his references to Hitler and Zionism] was before the Brexit referendum," he said.
"The internet has made things worse. Of course Brexit has divided the country and where there is division there are often problems.
"But that would have been the same if Remain had won a vote that was split down the middle almost 50/50.
"Just this week someone from the Lib Dems called me a traitor. It's the problem over the use of inflammatory language.
"It did used to come more from the Brexit side but not any more."
Mr Mann said he would continue to ensure that the Jewish community continued its "high level of civic engagement."
He said it was crucial the community played a full and visible role in the democratic process in troubled times.
"The Jewish community is the canary in the cage for humanity - whether you like or not," he said.
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