Emily Thornberry, the Shadow Foreign Secretary, has reiterated that “the next Labour government will recognise the state of Palestine”, but said that it would also seek to end the Palestinian Authority’s “officially sanctioned antisemitic incitement”.

Ms Thornberry, who was speaking at the annual lunch for Labour Friends of Israel [LFI], emphasised that there was "no place" in the party "for anyone who holds antisemitic views or who denies the right of Israel to exist." She added: "any people who hold those views must and will be drummed out of our party”.

The Labour Party, she continued, “will recognise the state of Palestine, because it is in the interests of Israel, the Palestinians and peace.”

However, Ms Thornberry also said that Labour “will make clear to the Palestinian Authority that officially sanctioned antisemitic incitement, and the glorification of suicide bombers, particularly to children and young people, must come to an end. Because peace can only be built by teaching children on all sides not to hate, but to love.”

She described in detail her visit to Israel in the early 1980s, where her father, a UN assistant secretary general, was stationed in Jerusalem.

Ms Thornberry was joined by the Israeli ambassador, Mark Regev, and Joan Ryan MP, the parliamentary chair of LFI, as speakers at the event. All three referred to the longstanding connection between Israel and Labour, with Ms Ryan noting that the party had publicly declared its support for the Zionist cause three months before the Balfour Declaration.

Mr Regev, however, went further, describing how “it was the British Labour Movement who called for the fledgling Jewish state to be recognised by the United Kingdom.

He added: “And I have with me here today a copy of one such motion, from the Manchester section of the constructional engineering union, today better known as Unite”.

That remark was met with laughter from the 300-strong audience, which included 60 Labour MPs. Under its current leadership, the Unite union has supported anti-Israel motions.

Mr Regev explained that the union's motion from December 1948 expressed “deep concern for the young Jewish state, which was defending itself against combined Arab aggression by the armies of Lebanon, Syria, Jordan, Iraq and Egypt. And it called upon the Foreign Secretary to recognise Israel, a year and a half before it decided to do so”.

However, the ambassador warned that “a Palestinian state that does not recognise the Jewish state is no solution. It would only serve as a vehicle to further perpetuate the conflict.

“I urge Labour to avoid the temptation of rushing towards a quick fix that ignores realities. Just as I urge Labour never to express solidarity with those whose aims are diametrically opposed to the peace and reconciliation we all seek.”

Joan Ryan described how she was “ashamed - and we should all be ashamed – of some of the language we have seen used by members of the Labour Party when discussing Israel… age-old tropes about international conspiracies and Jewish power, the suggestion that Jews are manipulating allegations of antisemitism for their own ends, and, most pernicious of all, the attempt to link Zionism and Nazi Germany.”

She also described the “grotesque spectacle of a speaker at a fringe meeting at Labour Party conference – a fringe meeting that was in the official conference guide – asking the question: ‘Holocaust: yes or no’; leaflets being distributed to delegates quoting the words of Reinhard Heydrich, the architect of the Final Solution, and some supporters of the current leadership taking to the airwaves and refusing to condemn Holocaust denial.”

She added: “Our party does not have a problem with ‘all forms of racism’. It has a problem with antisemitism. And we will never be able to confront it until we acknowledge that fact.

“This is not a peripheral issue. It warps the important debate about how a future Labour government can help bring about an end to the tragic conflict between Israel and the Palestinians. It sullies our party’s reputation and betrays its history.

“It strikes at the very core of what our movement is about and should offend the conscience of every Labour party supporter, member and elected official.”