Foreign Secretary William Hague says the UK is set to abstain in a key vote on whether the Palestinians should get upgraded diplomatic status at the UN. The UN General Assembly will decide whether to recognise the Palestinians as a "non-member observer state".
Mr Hague said the UK would not vote against but needed assurances that the Palestinians would eek negotiations with Israel "without pre-conditions" in order to be able to back the move.
Without these, the UK would abstain.
An upgrade from their current "permanent observer" status would allow the Palestinians to participate in UN debates and improve their chances of joining UN agencies and the International Criminal Court (ICC), although the process is neither automatic nor guaranteed.
Observers say the application is likely win approval in the 193-member UN General Assembly when it is put to a vote, because it needs only a simple majority to pass.
France, Spain and Norway are among those to be urging the UN General Assembly to recognise the Palestinians as a "non-member observer state".
According to the Palestine Liberation Organisation (PLO), more than 130 countries now grant the Palestinians the rank of a sovereign state.
Speaking last week, David Cameron said the UK had urged the Palestinians against putting the issue to the vote "in the short term" as they believed it would be counter-productive to the chances of kick-starting the peace process.
A lasting peace would not be brokered by the UN, he added, but only by the two sides sitting down and talking.
Labour have long backed the move, arguing it is an opportunity to "support the cause" of a two-state solution and would boost the position of moderate Palestinians intent on political progress.
The US and Israel oppose the move, regarded as a symbolic milestone in Palestinian ambitions for statehood.