Jeremy Corbyn is being accused of failing to take effective action against antisemitism by a senior member of his own party.
Jeremy Newmark, chair of the Jewish Labour movement, refused to say whether the party's record on dealing with antisemitism would affect votes next Thursday.
His comments come on the same day Jewish News, a major Jewish newspaper ran a damning front page after Corbyn refused to speak to the paper.
'Jeremy Corbyn appears to have failed to understand the nature of contemporary antisemitism in the same way that it's understood by most of its target group,' he said.
A poll last week revealed Theresa May held a 64-point gap over Corbyn among Jewish voters with just 13 per cent backing the Labour leader.
The Survation study for the Jewish Chronicle claimed 77 per cent of Jewish voters backed Theresa May.
In an attempt to tackle the perception Corbyn's leadership fuels antisemitism, Labour launched a 'race and faith' manifesto on Tuesday, promising to tackle hate crime and recruit 10,000 more police officers to work on community beats.
'Antisemitism is an evil which led to the worst crimes of the twentieth century. Every one of us has a responsibility to ensure that it is never allowed to fester in our society again,' it reads.
Chief executive of the Jewish Leadership Council, Simon Johnson, said 'this is probably the first election at which this has been an issue' to such an extent.
'People within the Labour party leadership are in no doubt about the concerns of the Jewish community,' he said.
