Jeremy Corbyn faced a new anti-Semitism storm last night after it was claimed he mocked a leading Jewish Labour MP behind her back by calling her 'the MP for Tel Aviv'.

The 'spiteful' jibe by the Labour leader was reportedly aimed at Louise Ellman, awarded a damehood by the Queen two months ago for her distinguished 30-year political career.

Mr Corbyn's alleged slur was revealed 24 hours after he tried to heal a rift with the Jewish community and admitted Labour had a 'real problem' with anti-Semitism.

Labour's troubles deepened last night when deputy leader Tom Watson warned the party would 'disappear into a vortex of eternal shame and embarrassment' and be unfit for government unless it resolved the anti-Semitism row.

In an newspaper interview, he also called on Mr Corbyn to drop without delay internal inquiries into Labour MPs Margaret Hodge and Ian Austin, who now face possible disciplinary charges after furious outbursts over the party's stance on anti-Semitism.

Mr Corbyn's claim that Labour was 'no threat to Jewish life in Britain' was undermined by claims that he and his aides have made sneering comments about Dame Louise.

A Labour spokesman last night strongly denied Mr Corbyn had privately called her the 'MP for Tel Aviv'.

In a separate development, fresh evidence emerged that Mr Corbyn repeatedly shared platforms with activists who likened Israel to Nazi Germany.

The Mail on Sunday has unearthed a previously unpublicised video showing him speaking at a pro- Palestine meeting in 2012 which included the reading of a poem that said the 'victims of Auschwitz' were now the 'torturers'.

Jewish campaigners said 'outrageous' verses of the poem read out at the rally breached part of the internationally recognised definition of anti-Semitism – the key section that Labour controversially left out of its watered-down version.

Incriminating footage: Jeremy Corbyn addressing a pro-Palestinian rally in 2012 at which another speaker compared Israel's actions to the Nazis

Dame Louise has frequently criticised Mr Corbyn for failing to tackle anti-Semitism. It has led to repeated attempts by Left-wing activists in the pro-Corbyn Momentum group to sack her as MP for Liverpool Riverside.

A former aide to Mr Corbyn told The Mail on Sunday that they had heard him describe Dame Louise sarcastically as 'the Honourable Member for Tel Aviv' when her name was mentioned. 'I was very surprised and when I asked other members of staff they said he often did it in private, though not to her face,' said the Labour insider.

The 'spiteful' jibe by the Labour leader was reportedly aimed at Louise Ellman (pictured)

Another senior Labour source said Dame Louise was commonly referred to as 'the Hon Member of Tel Aviv' by members of Mr Corbyn's staff. 'If her name crops up, or she appears on the office TV, they'll say, 'There she goes again, the Honourable member for Tel Aviv.' They can't stand her.' Last night, Stephen Pollard, editor of the Jewish Chronicle, condemned Mr Corbyn's 'spiteful' comment.

Born into a Jewish family in Manchester, Dame Louise, 72, was chairman of the Jewish Labour Movement until 2016 and is vice chairman of the Labour Friends of Israel. She denounced Mr Corbyn for hosting a Holocaust Memorial Day event during which the Israeli government was compared to the Nazis.

In 2016, she backed a motion of no confidence in Mr Corbyn by rebel Labour MPs.

A spokesman for Mr Corbyn said last night the claim that he had called Dame Louise 'the MP for Tel Aviv' was 'a fabrication'.

The disclosure of Mr Corbyn's role at the 2012 pro-Palestine rally follows claims last week that he chaired a meeting in Parliament in 2010 in which a speaker compared Israel's actions to the Nazis.

Video footage of the 2012 meeting hosted in Conway Hall, Holborn, London by the Palestine Solidary Campaign shows the poem Love Letters To Gaza being recited by an actress. It was reportedly applauded by Mr Corbyn. The poem refers to an attempt by an unofficial 'freedom' flotilla of ships to break the blockade imposed by Israel on the Gaza Strip in 2011.

It includes the lines: 'It is not now the Nazi state but Israel that blocks the seas./It is not Auschwitz that stops the ship that carries hope and messages,/But those that might have died there..../The victims are now the torturers.'

Mr Corbyn was also highly critical of Israel in his speech at the meeting, which featured a backdrop comprising a map showing Palestine in place of Israel.

Labour's anti-Semitism revolt grew last night as Emily Benn, granddaughter of late Left-winger Tony Benn, said the only way to solve Labour's anti-Semitic rift was to sack Mr Corbyn.

His statement was 'utter rubbish', tweeted former Labour parliamentary candidate Ms Benn, niece of senior Labour MP Hilary Benn.

'To refer to me as the 'MP for Tel Aviv' is to challenge my loyalty to this country,' said Dame Louise Ellman of Corbyn's comment

'No responsibility taken for the anti-Semitism and those anti-Semites he has supported for years. Labour has become an institutionally anti-Semitic Party under Jeremy Corbyn. It will not change while he is leader.'

Dame Louise said last night: 'If this is correct, I am appalled that a potential Prime Minister would use language of this sort against one of his own MPs.

'To refer to me as the 'MP for Tel Aviv' is to challenge my loyalty to this country.

'A key part the internationally accepted code on anti-Semitism which the Labour Party wants to dilute specifically states it is anti-Semitic to accuse Jews of being more loyal to Israel than to their own country.'

A Labour spokesman said last night that the allegation that Mr Corbyn had called Dame Louise the 'MP for Tel Aviv' was 'entirely untrue'. He also said, in relation to the 2012 pro-Palestinian meeting, that Mr Corbyn 'was not responsible for everything said at every meeting he has ever attended'.