Western and Arab governments try to persuade Moscow to accept resolution calling on Bashar al-Assad to step down

Russia is facing intensive efforts by western and Arab governments to persuade it not to veto a UN resolution calling on Syria's president, Bashar al-Assad, to surrender power and end the country's escalating crisis.

Ambassadors of the 15 members of the UN security council were meeting in New York late on Wednesday to assess support for an Arab-led drive to secure a peaceful end to the 10-month crackdown.

No vote is likely before Friday and it is unlikely it would be delayed beyond next Tuesday, diplomatic sources said, revealing attempts to convince Russia not to block the widely-supported draft text.

Western officials indicated that a Russian abstention would also be a satisfactory outcome, given the close relationship between Moscow and Damascus.

Russian officials suggested that a vote was not imminent. China, one of the five permanent members of the council, is thought likely to follow Russia. India, Pakistan and South Africa, which are all non-permanent members, were said to have softened their earlier objections.

Russia's ambassador to the EU, Vladmimir Chuzhin, said the current text was "missing the most important thing: a clear clause ruling out the possibility that the resolution could be used to justify military intervention in Syrian affairs from outside.

"For this reason I see no chance this draft could be adopted," he said.

Russia's UN envoy, Vitaly Churkin, told reporters in Moscow: "If it is a text that we consider erroneous, that will lead to a worsening of the crisis, we will not allow it to be passed. That is unequivocal."

The US, Britain and France, backing a resolution that closely follows an Arab League plan, have insisted that it could not be used to authorise military action. Hillary Clinton, the US secretary of state, dismissed comparisons with Libya, where the Nato-led intervention that helped overthrow the Gaddafi regime still rankles with Moscow.

Western diplomats made clear that they were exploring ways to provide Russia with the assurances it wanted, but pointed out that the resolution is under Chapter VI of the UN charter, which cannot authorise armed action.

"We will be flexible and take on Rusian concerns," said one offiical. "It will take a lot of effort to get them to support this, but they are feeling uncomfortable. We don't see any reason why this should be rejected."

Russia has also described the resolution as a recipe for regime change. The Arab League and its western supporters insist it is not, calling it the best way out of the bloodiest current chapter of the Arab spring - in Clinton's words, "a path for a political transition that would preserve Syria's unity and institutions".

The Arab League has called on Assad to hand power to his deputy and form a unity government with the opposition.

According to the UN, at least 5,400 people have been killed since the uprising began 10 months ago. Syrian opposition sources say the figure could be much higher. The Syrian government says it is facing an international conspiracy supporting "armed terrorist gangs".

Amnesty International also called on Russia to stop blocking a UN resolution — after doing so last October. "Russia's threats to abort a binding UN resolution on Syria for the second time are utterly irresponsible," said José Luis Díaz, Amnesty's representative to the UN. "Russia bears a heavy responsibility for allowing the brutal crackdown to continue."

The latest diplomatic wrangling came on another day of violence across Syria, with reports from opposition sources that 52 people had been killed, mostly in the Damascus region. The Syrian Revolution General Commission said that 17 people had been killed in Homs and five in Deraa in the south, where the unprecedented unrest began last March. The Local Co-ordination Committees in Syria put the figure at 63 people killed.