The annexation of land in the West Bank and Jordan Valley serves “one function” for the Israeli government and would end hopes of a Palestinian state, the head of the Palestinian mission to Britain said.
Israeli Prime Minister Benjamin Netanyahu is due to begin plans for annexation on July 1.
“Netanyahu is telling the world and telling us, ‘It’s Israel from the river to the sea’,” said Husam Zomlot, a high-ranking diplomat who served previously as the head of mission in Washington.
Appearing on a podcast alongside Britain’s former Middle East minister Alistair Burt, Mr Zomlot said the annexation would create a “slave-master relationship” on Palestinian land and end efforts to reach a two-state solution.
“It’s an announcement, a statement, a commitment to end the concept of partition,” he said.
A major international effort to resolve the long-running dispute over the Palestinian Territories was needed to prevent the conflict from destabilising the region, he said.
Mr Zomlot blamed the US for failing to act as an effective mediator in the conflict, a role over which Washington had enjoyed a “monopoly” for several decades.
“If we really want to implement the two-state solution, we must create an international peacemaking mechanism," he said. "The US alone cannot do it.
“We need the world, we need the United Kingdom, we need the European Union, we need Russia, China, Brazil, South Africa, we need everybody at the table.
"And of course, we need the Arab world.”
Mr Zomlot echoed warnings from Arab countries that Israeli annexation plans would have a significant effect on the region.
“I believe the Arab world when they say this is going to lead to damaging and undermining the regional stability and regional security,” he said.
Mr Zomlot praised King Abdullah of Jordan for “speaking in solidarity with the people of Palestine”, but said powers in the region and beyond needed to do more to support the pursuit of peace.
“So far, none of the actions coming from the region, or the rest of the international community, has really changed the calculus,” he said.
Arab nations, including the UAE, have condemned the annexation plans, which Mr Zomlot said threatened the rules-based order that has governed international affairs since the end of the Second World War.
“The premise of that order is the inadmissibility of acquiring land by force,” he said.
He dismissed as nonsense Israel’s claim that it needs to control the Jordan Valley security, as “nonsense”.