By Mohammed Abbas

LONDON (Reuters) - Britain condemned Israeli settlements on Monday as "deliberate vandalism" of efforts to establish a Palestinian state, bolstering Palestinian President Mahmoud Abbas as negotiators attempt to revive moribund peace talks.

Deputy Prime Minister Nick Clegg's comments were some of Britain's strongest yet on the Middle East's most intractable conflict, and come as Abbas tours Europe while negotiators from both sides undertake initial discussions on resuming full talks.

The exploratory discussions began on January 3 and followed a long break in negotiations after Abbas suspended talks 15 months ago over Israel's expansion of Jewish settlements in the occupied West bank, where Palestinians want to found a state.

All parties to the talks have accepted the ultimate goal of a "two-state solution," which would see a Palestinian state established alongside Israel. The sides remain divided over its borders, the fate of Palestinian refugees and other issues.

Israel says such issues can be resolved only at talks with no preconditions. Palestinians say Israel must first halt settlement building, which they believe moves the goalposts while talks are under way and gives Israel incentive to stall.

"Once you place physical facts on the ground which make it impossible to deliver what everyone has for years agreed is the ultimate destination, then you do immense damage," Clegg told reporters during a visit to London by Abbas, referring to settlements interfering with the two-state solution.

"It's an act of deliberate vandalism to the basic premise upon which negotiations have taken place for years and that is why we have expressed our concerns as a government in increasingly forceful terms," he said.

He prefaced his comments by saying there was no stronger supporter of Israel than himself.

In February last year, Britain and almost all other members of the United Nations Security Council backed a resolution condemning settlement building as illegal and a major obstacle to peace.

The resolution was vetoed by the United States, which says it wants Israel to stop settlement construction but believes international condemnation is unhelpful.

Abbas, who is also due to visit Berlin and Moscow, welcomed the deputy prime minister's comments.

"This is exactly what we had wanted to hear officially from government of the United Kingdom," he said, speaking next to Clegg. He reiterated his call for a halt to settlement building.

Abbas did not say why he was considering returning to the negotiating table now despite continued settlement building, but Clegg said the Arab Spring had ushered in a period of change that could make negotiations more fruitful.

"If there was any time for real progress, then it is now at a time when so much change and transformation has taken place throughout the region," Clegg said.

Abbas said he had received no new proposals from Israeli Prime Minister Benjamin Netanyahu, but that Palestinian negotiators were still scheduled to meet their Israeli counterparts two or three more times.

The "Quartet" of international peace mediators - the United States, Russia, the European Union and the United Nations - sought in October to revive the peace talks, which broke down weeks after they began in 2010.

The group wants the two sides to state their positions on the borders and security arrangements of a future two-state solution by January 26.

Last week, Israeli Foreign Minister Avigdor Lieberman, a hardline coalition partner to Netanyahu who is often sidelined in statecraft, dismissed the newly rekindled diplomatic contacts.

"They (the Palestinians) are preparing a groundwork of excuses to shift responsibility for the talks' failure to Israel," he said, according to an official transcript of a parliamentary briefing.

(Reporting by Mohammed Abbas; Editing by Peter Graff)