A Labour government under Jeremy Corbyn could spell the end to Britain’s reputation as an “honest broker” in attempting to resolve the conflict between Israel and the Palestinians, the leading think tank BICOM has warned.

It is also suggested that Mr Corbyn's approach to the Middle East  would "drive a wedge" between the UK and "both Israel and Western-aligned Arab states", as well as threatening Israeli investment in Britain.

Speaking ahead of the publication of new briefing paper on Labour Party foreign policy in the Middle East,  James Sorene, Bicom’s chief executive, said: “I was taken by the idea that we had almost taken for granted for decades now that there was this political consensus between the main political parties in the UK of support for Israel and a negotiated two-state solution with Palestinians.

“When Jeremy Corbyn issued his statement on the night of the Balfour centenary celebrations calling for recognition of a Palestinian state and calling for international pressure on Israel, you realise the consensus was broken.”

The report finds that while Labour’s approach to the Iran nuclear deal is unlikely to differ greatly from the current government, as Prime Minister, the Labour leader would seek much warmer relations with the of the Islamic Republic.

This is in stark contrast to the current government, which considers Iran's policies a threat to the stability of the region. 

Mr Sorene said: ”Labour’s foreign policy is an issue of deep concern to many of Britain’s closest allies in the Middle East, and around the world. Decades of intelligence and defence cooperation are at risk.

“Booming bilateral trade, inward investment and job creation could be in peril, precisely when we need them the most as we leave the EU.

"If Labour moves too close to Iran, and Hamas and Hezbollah then this will also undermine international efforts to fight terrorism and even limit the sharing of vital intelligence that saves British lives. 

“If Labour recognise a Palestinian state and adopts the Palestinian position of putting international pressure on Israel it could lose its influence with Israel to solve the Israeli-Palestinian conflict.

"Moves towards a boycott of settlement goods could provide a slippery slope to wider boycotts of Israel and this would seriously harm Britain-Israel relations and impair an expanding trade partnership that creates thousands of UK jobs."

Mr Sorene said that all the evidence suggested a Labour government under Mr Corbyn would recognise a Palestinian state “very quickly”.

He added: “That would have a very significant effect on Britain Israel relations.

“And if they then positioned the UK as this very pro-Palestinian country they would end up being the most pro-Palestinian in the whole of Europe.

“This would put the UK really out there and significantly impair the UK’s ability to play this important role as the honest broker.

“People don’t always realise Britain has had this really good relationship with both Israel and the Palestinian Authority. It is very significant – but it could blow that.”

Mr Sorene said the main objective of the new foreign policy paper was to “put everything Labour has said they would do together as a piece of analysis”.

He also warned that a recent speech by Shadow Foreign Secretary Emily Thornberry in support of a boycott of Israeli  settlement products could be the beginning of a “slippery slope” towards a wider boycott of produce from the Jewish state.

Responding to the Bicom report, a spokesperson for Mr Corbyn said: “Labour supports the call most recently made by UN Secretary General Antonio Guterres for a comprehensive peace in the Middle East based on a two-state solution – a secure Israel alongside a secure and viable state of Palestine.

"Jeremy Corbyn has consistently made the right calls in the interests of Britain's security and international peace, from the war in Libya to his opposition to the invasion and occupation of Iraq, which had catastrophic consequences in the region and made us less safe at home.

"Labour has demanded an independent, UN-led investigation into evidence of violations of international humanitarian law in Yemen, including air strikes on civilians by the Saudi-led coalition, a halt to UK support for the Yemen war and action to cut off the funding of terror networks from Saudi Arabia and allied states.”