The Palestinians’ bid for upgraded, non-member observer state status at the United Nations received major boosts Tuesday as, after France, Spain and Switzerland announced that they would support the move, Britain indicated that it might do likewise, subject to certain assurances from the Palestinian leadership.

On Wednesday, Norway and Denmark also said they would vote “yes” on the Palestinian proposal. Australia said it will abstain.

Although the motion appeared to be virtually assured of passage at the General Assembly in any case, Western powers had hesitated to offer their support while the United States and Israel opposed it.

But Britain reportedly indicated it could back the Palestinian delegation in the UN vote on Thursday, on the condition that Palestinian Authority President Mahmoud Abbas commit to not using the new status to pursue war crimes charges against Israel in the International Criminal Court or the International Court of Justice, and to resume peace talks with the Jewish state. Britain’s Foreign Secretary William Hague has reportedly been holding telephone talks with Abbas on the issue.

PA official Tawfiq Tirawi had told Reuters that the Palestinians would take Israel to task for Yasser Arafat’s assassination at the International Criminal Court in the Hague.

“We need proof in order to find those who are behind this assassination and take it to the ICC,” he said. “When we have proof, we will go to the ICC for it to be our first case to try those whose policy is assassinations,” he added.

Later on Tuesday, though, Palestinian UN observer Riyad Mansour told a news conference at the United Nations that the Palestinians would not rush to sign up to the International Criminal Court.

The British government has “signalled it would change tack and vote yes if the Palestinians modified their application,” The Guardian said Tuesday. “Whitehall officials said the Palestinians were now being asked to refrain from applying for membership of the international criminal court or the international court of justice, which could both be used to pursue war crimes charges or other legal claims against Israel. Abbas is also being asked to commit to an immediate resumption of peace talks ‘without preconditions’ with Israel. The third condition is that the general assembly’s resolution does not require the UN security council to follow suit.”

The Guardian also said the PA has been telling the US and Europe that if it does not receive support for its UN bid, Hamas would be strengthened, and the assertion that violence rather than diplomacy pays, potent in the wake of Hamas’s claimed “victory” after the recent eight-day conflict with Israel, would be further vindicated among Palestinians.

Some European diplomats have warned that “failure to support Abbas could risk further undermining his increasingly weak position, to Hamas’s advantage,” the Guardian said.

It claimed the US and Britain “are attempting to weaken the impact of a UN vote” and quoted Palestinian officials saying Britain and the US have “pressed Abbas to sign a confidential side letter, which would not be presented to the UN general assembly, committing the Palestinian Authority not to accede to the ICC.”

Earlier Tuesday, AP reported that France had become the first major European country to come out in favor of the Palestinian motion, with the timing of the announcement appeared to be aimed at swaying other European nations. Switzerland announced it would vote “yes” while Germany was expected to vote “no.”

French Foreign Minister Laurent Fabius told Parliament that France had long supported Palestinian ambitions for statehood and “will respond ‘Yes’” when the issue comes up for a vote “out of a concern for coherency.”

By that point, Israel had already backtracked on its threat to dismantle the Oslo Accords in response to the bid.

“We won’t cancel any of our agreements,” a senior official said. However, the official said, Jerusalem still considers Abbas’s unilateral step to seek nonmember state status at the UN a grave violation of agreements signed with Israel, and vowed that Israel would “respond accordingly.”

Israel will quietly await Thursday’s vote before deciding on sanctions, the official said. If the Palestinians go ahead with the vote on Thursday, Israel will consider a series of punitive steps, such as seeking to call in Palestinian debts, he added, by way of example.