London, England - US President Donald Trump's recognition of Jerusalem as the capital of Israel signals the "official adoption of the Israeli narrative", a prominent Arab Knesset member said, one week after Washington confirmed it was bringing forward to May the date the US embassy would be moved from Tel Aviv to the Holy City.

Ahmad Tibi, speaking at a conference on Saturday in London titled, Is President Trump legalising the occupation?, claimed: "The most dangerous element of Trump's embassy decision is that it says Israel has the right to decide where its capital is, simply because parliament and the Supreme Court are there."

"This is an official adoption of the Israeli narrative."

Trump sent shock waves around the world after announcing in December that he recognised Jerusalem as Israel's capital, as he pledged to move the US embassy to the city.

US Vice President Mike Pence had earlier claimed the embassy move would take place in 2019, but the US Department of State said on February 23 that the relocation would happen in May this year, to coincide with the 70th anniversary of Israel's declaration of independence.

The announcement was seen as a provocation.

Palestinians mark May 15 as Nakba Day, or the "catastrophe", when they commemorate the mass displacement of Palestinians to make way for the state of Israel.

Expansion of the embassy will take place by the end of 2019, the US Department of State said.

The move reverses decades of US foreign policy.

'US cannot be a broker in the conflict'

At the London conference, hosted by Middle East Monitor, politicians, activists and academics repeatedly noted the potentially dangerous consequences of Trump's move.

The US decision has already prompted deadly protests in Palestine and solidarity rallies across the world.

Tibi rejected Trump's claims to be drafting the "ultimate deal" in the long-standing conflict, saying it was clear the US could no longer be considered an appropriate mediator.

"Telling the Israelis, 'You can have it all', and telling Palestinians, 'You can have nothing', means there will be no deal. There is a double standard which means the US cannot be a broker in the conflict," he said.

Trump's decision fails to solve outstanding issues in the conflict, such as the return of Palestinian refugees, he said.

Other speakers echoed Tibi's sentiments, saying the move highlights the unequal power dynamics between Israel and the Palestinians.

"We never had real negotiations [with Israel], because negotiations can't take place in such asymmetrical power relations," said Manuel Hassassian, the Palestinian Authority's diplomatic representative to the United Kingdom.

Professor Nicolas Boeglin, project officer at the Inter-American Institute for Human Rights, suggested that there were still legal avenues for the international community to challenge the decision to recognise Jerusalem as Israel's capital, through pushing for the recognition of Palestine as a state, and requesting a legal response to Trump's move at the International Court of Justice.

Urging further action, he said: "The time has come to do more than write a single communique condemning the decision.

"We owe a debt to the Palestinian people, too much time has passed without a resolution."

Britain's royal visit to Israel condemned

The latest developments, several speakers said, stemmed from the failure of the Oslo peace process.

Hassassian said the incrementalism of Oslo had left Palestinians stuck "between the historically inevitable and the politically impossible".

Meanwhile, the March 1 announcement that the UK's Prince William will make the first British royal visit to Israel in the summer, after years of stalled trips from the royal family, angered Palestinian delegates at the London event.

Ghada Karmi, a leading Palestinian academic, activist and writer, said at the London event that it "feels like an approval of the 1917 Balfour Declaration" - particularly as the prince's visit will take place shortly after the embassy move.

Israeli Prime Minister Benjamin Netanyahu welcomed news of the visit, writing on Twitter that Prince William would be welcomed with "great affection".

The legacy of Britain's role in Palestine was also highlighted by Sami Abu Shehadeh, chief executive officer of the Yaffa Youth Movement, who said: "Trump's declaration on Jerusalem would not be as important as it is without the historical context of British colonialism in Palestine, and the Balfour Declaration."