The UK government is to have a fresh debate on whether it should vote to recognise Palestine as a sovereign state.

The UN will this month consider an application by the Palestinian president, Mahmoud Abbas, for observer status, which would imply recognition of the territory as a sovereign state, something Israel and the US have opposed.

The UK plans to abstain on 29 November, but the Liberal Democrat leader, Nick Clegg, is to urge his Conservative coalition partners to change their vote to "yes". Senior party sources say the deputy prime minister is convinced Palestine will win the UN vote.

Clegg will lobby David Cameron and the foreign secretary, William Hague, arguing that last week's surge in tension between Israel defence forces and Hamas increases the need to support the more moderate Abbas, said a source.

He said: "Nick feels because they are going to be definitely doing it [applying], and clearly going to win the vote, it's important for us to vote for them to have observer status and not abstain."

The Palestinian application follows a vote to reject their application for full UN status last year.

A majority of Europeans want their governments to vote in favour of Palestine at the UN, polls have revealed.