Labour MP Dame Louise Ellman has launched a devastating attack on Jeremy Corbyn, saying she would "understand" why British Jews "would seriously consider" leaving the country if he entered Downing Street.

Speaking at the Labour Friends of Israel's annual reception at Labour's conference in Brighton, Dame Louise, who chairs the group, said that when she joined the party 50 years ago she "never dreamed" it would led "by a man who would call Hezbollah and Hamas 'friends'."

The Liverpool Riverside MP, who has faced constant attacks from far-left activists in her constituency, told the audience at Brighton's Hilton Hotel: "Like many of you, I have viewed with horror the rise of antisemitism in the Labour Party and the growth of an obsessive, irrational hatred towards the State of Israel.

 "Too many have averted their eyes from this tragic situation. Too many have sought to blame the victims and question their motives. 

"And too many claim to abhor racism 'in all its forms', while ignoring the racism against Jews which stalks party meetings, social media and the highest institutions of the party.

 "Let us never forget that not to speak and not to act are themselves choices. Antisemitism matters to Jews and non-Jews alike.

 "It is the ally of the populist, the crank, and the conspiracy theorist. It is nothing less than a poison which coarsens, corrodes and warps society itself. 

"We have seen what it has done to the Labour Party.

Turning her attention to the Labour leader as she spoke in front of around 150 guests, including Israeli Ambassador to the UK Mark Regev and Board of Deputies President Marie van der Zyl, Dame Louise said: "Who would you label a propagator of the blood libel a 'very honoured citizen';

"And would peddle and endorse vile, trope-laden conspiracy theories.

"When I became a Labour councillor 49 years ago, I never imagined that Jewish supporters, members, councillors and MPs would be abused, threatened and driven from the party, and that it would find itself the object of an investigation by one of Labour’s proudest creations, the Equalities and Human Rights Commission.

 "And when I had the honour to become an MP on the day Labour returned to government 22 years ago, I never believed we would see the day when many British Jews would so fear our leader, that they would seriously consider leaving the country if he entered Downing Street.

"I not only understand those fears. I share those fears. For what does it say about Jeremy Corbyn that he looks at a grossly antisemitic mural and apparently cannot see how grotesque and offensive it is;

"That he was active in an antisemitic Facebook group whose members discussed reading Mein Kampf, used the terms 'ZioNazi' and 'JewNazi' and discussed whether the BBC was controlled by Zionists, but, again, never seemed to see any of this; 

"And that he was willing to take the pay of Press TV, the mouthpiece of a regime which denies the Holocaust and threatens to annihilate Israel – and even now refuses to apologise for having done so.

"What does it tell us about Jeremy Corbyn that he can describe the words of Hamas terrorists as 'fascinating and electrifying'?

"Men who blew up families as they sat enjoying a meal in a pizza restaurant.

"Men who murdered Israeli teenagers as they excitedly waited to enter a club on a night out with friends."Men who butchered Holocaust survivors as they shared a Passover Seder.

"And what are we left to think when Jeremy Corbyn finds the time to lay wreaths at the graves of those who masterminded the torture and murder of Israeli athletes at Munich, but repeatedly refuses invitations to visit Yad Vashem – the museum and monument to the greatest crime in human history?

"Yesterday, on the conference floor, we saw a standing ovation given to a delegate who denied there was any antisemitism in the Labour Party. 

 "Not only that but a motion supporting boycotts was passed for the first time in Labour history. 

"Let us be clear about what this means, the only country the Labour party calls to boycott is the world’s only Jewish state.

"This cannot continue. This is not compatible with Labour’s values. This is not the party I joined

"It is our duty to raise our voices. To be louder. To do all we can to fight the poison of antisemitism in the Labour Party. "There is no greater fight than the struggle against racism and prejudice. "They are evils that one day we can and we shall overcome."

Dame Louise's speech came hours after Mr Corbyn had delevered his speech to the Brighton Conference floor.

She also stressed her belief that a two state solution was the only way to resolve the Middle East crisis between Israel and the Palestinians.

Later Adrian Cohen, LFI's Lay Chair blew the shofar in a symbolic display that was applauded by those in attendance.

LFI had cancelled its planned promotional stall at Labour conference earlier in the week over fears that young volunteer staff would be subjected to abuse.