Germany said it would not support the diplomatic upgrade for the Palestinians at the United Nations, joining Israel and the United States which say the only genuine route to statehood is through a peace accord from direct talks with the Jewish state.
Granting Palestinians the title of "observer state" short of full U.N. representation could allow them access to the court and some other international bodies.
Palestinian President Mahmoud Abbas is leading the campaign and several European governments are eager to give him their support after an eight-day conflict this month between Israel and Islamists in the Gaza Strip, who are pledged to
Israel's destruction and oppose his efforts towards a negotiated peace.
Talks have been stalled for two years, mainly over the issue of Israeli settlements in the West Bank, which have expanded despite being deemed illegal by most of the world.
Abbas has pledged to relaunch the peace process immediately following the U.N. vote, the Swiss Foreign Ministry said as it gave its backing for fuller Palestinian statehood.
With overwhelming support from the developing world, the Palestinians appear certain to earn approval in the 193-member U.N. General Assembly for the status upgrade on Thursday.
Austria, Denmark and Spain also said they would vote for the upgrade after France gave its approval on Tuesday.
Britain - like France and the United States a permanent member of the U.N. Security Council - said it would not oppose the move but needed more assurances to give its full support.
"The first is that the Palestinian Authority should indicate a clear commitment to return immediately to negotiations without preconditions," Foreign Seretary William Hague told parliament.
"The second assurance relates to membership of other specialised U.N. agencies and action in the International Criminal Court," he added.
Rights groups said that stance contradicted Britain's stated commitment to accountability for serious crimes.
"Pressing the Palestinians to forego international justice is wrong in principle," said New-York based Human Rights Watch.
Germany said it would oppose the Palestinian bid. Berlin has close ties with Israel and has strongly backed its right to hit back against rocket attacks from Gaza during the latest upsurge of violence in the region.
"Our goal in all this is to prevent further negative effects on the already difficult Middle East peace process," German foreign ministry spokesman Andreas Peschke said.
He reiterated Germany's support for a two-state solution as the final result of a "just and negotiated settlement".
In Ramallah in the West Bank, senior Palestine Liberation Organization official Hanan Ashrawi said the positive responses from other European states were encouraging and sent a message of hope to all Palestinians.
"This constitutes a historical turning point and opportunity for the world to rectify a grave historical injustice that the Palestinians have undergone since the creation of the state of Israel in 1948."
Israel and the United States have mooted withholding aid and tax revenue that the Palestinian government in the West Bank needs to survive. Israeli Foreign Minister Avigdor Lieberman has also viewed options that include bringing down Abbas.
Israeli, British and U.S. diplomats had tried to persuade the Palestinians to drop their upgrade bid. When that foundered, they focused on trying to get the Palestinians to guarantee that they would forego complaining about Israel to the ICC.
The court prosecutes people for genocide, war crimes and other human rights violations.
The Palestinian U.N. observer, Riyad Mansour, said the Palestinians would not rush to sign up to the ICC if they win the U.N. status upgrade. But seeking action against Israel in the court would remain an option, he told a news conference at the United Nations on Tuesday.
Mansour said that if Israel continued to violate international law, particularly by building settlements in the West Bank - territory Israel captured in the 1967 Middle East War - then the Palestinians would consult with friends, including Europe, on what to do next.
The United States has suggested aid for the Palestinians - and possibly some funding for the United Nations - could also be at risk if the Palestinians win the U.N. upgrade. Israel has said it may cancel the Paris Protocol, an economic accord it maintains with the cash-strapped Palestinian Authority.