Foreign Secretary William Hague has spoken to his Russian counterpart Sergey Lavrov amid continuing anger at Moscow's decision to block a United Nations Security Council resolution on Syria.
The Foreign Office said the two men discussed the latest situation in the country by telephone for around half an hour following Mr Lavrov's visit to Damascus.
Mr Hague insisted that Western countries were not contemplating military intervention in Syria but said he believed that President Bashar al Assad should now step down.
He also tackled Mr Lavrov about reported Russian arms sales to the regime. Mr Lavrov retorted that such sales were not illegal.
In the Commons, David Cameron was dismissive of the Russia's unilateral attempt at a diplomatic intervention, saying he had "very little confidence" that it would end the fighting.
He told MPs at Prime Minister's Questions that the international community had now to work with Syrian opposition groups both inside and outside the country to co-ordinate a concerted opposition to Assad's regime.
"I think the bloodshed in Syria is absolutely appalling. I think the Russians have to look at their consciences and realise what they have done," he said.
"But the rest of the world will keep on fighting as hard as it can to give the Syrian people a chance to choose their own future."
