Jeremy Corbyn was accused of lying on live television last night over his handling on the Labour anti-Semitism crisis - by a Jewish party activist.
Watched by million on ITV Mr Corbyn tried to squash accusations that his party has failed to root out anti-Semites.
The Labour leader said anti-Semitism was 'an absolute evil and scourge within our society' while insisting the party was treating the issue 'very, very seriously'.
But to many people, his promises fell flat and were rounded upon by both rivals and members of his own party.
Jewish Labour Movement chairman Peter Mason was scathing about his party leader's 'disgraceful' response to internal racism.
Reacting to a clip of Mr Corbyn insisting he has 'taken action' to rid Labour of anti-Semitism, he tweeted: 'This is a lie There are at least 130 outstanding anti-Semitism cases, some dating back years, that still haven’t been dealt with.
'The Party haven’t bothered to investigate the cases properly or make decisions.
'Corbyn and Labour’s total failure to deal with anti-Semites has seen it be investigated by the EHRC [Equality and Human Rights Commission] for institutional anti-Jewish racism.'
Accusations of anti-Semitism have dogged Mr Corbyn since he became leader in 2015, and earlier this year saw six Labour MPs quit the party.
Mr Johnson confronted his opposite number on the ITV stage about the issue, claiming: 'It's a complete failure of leadership what's happened with anti-Semitism, but the failure of leadership is even worse when you look at what is happening on their Brexit policy.'
The Labour leader replied: ‘Anti-Semitism is an absolute evil and scourge within our society.
‘I have taken action in my party, where anyone who has committed any anti-Semitic acts or made any anti-Semitic statements, they are either suspended or expelled from the party and we’ve investigated every single case. We do take this very seriously indeed.’
Karen Pollock, from the Holocaust Educational Trust, said Mr Corbyn’s claims were ‘blatantly untrue’.
‘Dealt with all incidents of anti-Semitism? Expelled all guilty? Done everything to fight racism? COME OFF IT. You can say what you want, no come back, no scrutiny. Even when it is blatantly untrue.’
Jeremy Corbyn was also accused of making notorious society paedophile Jeffrey Epstein 'more Jewish' last night after mis-pronouncing his surname live on television.
The Labour leader was said to have given the surname of the American, who killed himself in prison earlier this year, a Germanic twist.
During the ITV live leaders' debate he called the child abuser 'Ep-schtine', sparking fury on social media - after Boris Johnson pronounced Epstein correctly.
David Baddiel led criticism of Jeremy Corbyn for his pronunciation. When Twitter user Alec Feldman speculated that the Labour leader had made Epstein sound 'more Jewish', the comedian and writer tweeted: 'Every Jew watching noticed that.'
And Jewish Tory peer Lord Finkelstein said that 'calling me Finkel SHTEIN is one of my tests' for anti-Semitism.
The Labour leader and Prime Minister answered questions on the billionaire predator and his relationship with Prince Andrew during the live head-to-head.
Both expressed sympathy for the victims of Epstein, the convicted sex offender who killed himself while facing trafficking charges.
The programme was watched by more than seven million people at its peak, with an average audience of 6.7million.
Viewers at home branded Corbyn an anti-Semite, with one nicknaming him 'Jezbollah' in a reference to his past remarks about his 'friends' in the Islamist paramilitary group Hezbollah.
As some people leapt to the politician's defence, Twitter user @leekern13 wrote: 'To the idiots saying we should pronounce things the way they are spoken in their country - He was an AMERICAN.
'He was born in New York. He wasn't German of generic "Jew"- he was American and his name was Epstein. Corbyn tried to emphasise aliens. He otherised Jews. Again.'
The fury came after Johnson and Corbyn refused to back Prince Andrew when asked whether of not he is fit for purpose during their leadership debate.
During a quickfire round the last segment of the debate on ITV, the Prime Minister and Leader of the Opposition were asked about the Duke of York.
It comes as the prince is facing heavy criticism this week over his friendship with paedophile financier Jeffrey Epstein.
Hosting Tuesday night's leadership debate in Salford, Julie Etchingham asked the Labour and Tory leaders: 'Is Prince Andrew fit for purpose?'
Corbyn said: 'Before we discuss Prince Andrew, I think we should discuss the victims that are there because of what Epstein was doing and I think there are very, very serious questions that must be answered and nobody should be above the law.'
Johnson said: 'All our sympathy should be with the victims of Jeffrey Epstein and the law must certainly take its course.'
It came as follow-up to a question sent in by a viewer watching at home. The original question sent in to ITV was: 'Is the Monarchy fit for purpose.'
Corbyn fired back that it 'needs a bit of improvement' but Johnson followed with 'the institution of the monarchy is beyond reproach'.
Since Andrew's Newsnight appearance five huge names - including Aon and KPMG - dropped their financial backing for his charity. He spoke with Emily Maitlis in the interview, which aired on the BBC on Saturday.
In the interview, Andrew denied having sex with Epstein trafficking victim Virginia Roberts, who said she slept with when she was 17.
In his car crash interview, Andrew questioned whether a picture showing him with Ms Roberts - now Giuffre - was accurately showing him with his hand around her waist at the London home of Epstein's girlfriend.
Viewers responded with fury at his claims, which included that he wasn't sure whether it was taken in London because he wasn't wearing a full suit.