William Hague issues plea to Russia to halt Syria's slide into civil war

William Hague issued an ultimatum to Russia last night (Sunday) to intervene in the Syrian crisis before it was too late, warning that the massacre of more than 100 people, including 30 young children, had taken the country to the brink of civil war.

Speaking shortly before boarding a flight to Moscow for meetings with his counterpart Sergei Lavrov today, Britain's foreign secretary said that Russia faced a stark choice between using its leverage with the Assad regime or risking its last bastion of influence in the Middle East descending into chaos.

Urging Moscow to put its full weight behind the six-point United Nations plan for Syria brokered by the former secretary general, Kofi Annan, he said: "The Russians have a great deal of leverage over the Syrian regime.

"We've had many differences of view over Russia at the Security Council, but Russia does support the Annan plan and so I hope Russia will redouble its efforts to get the Assad regime to implement that plan," he said. "It's not in the interests of Russia, just as it's not in the interests of anybody in the world, for Syria to descend into an even bloodier situation and into full-scale civil war and that is now the danger."

Annan, the joint UN-Arab League envoy, is due to arrive in Damascus this morning for talks over the six-point plan to end the violence and begin a political process in Syria.

Hague, who said he was "sickened" by the images from the massacre at Houla, has also called an emergency session of the UN Security Council and summoned Syria's most senior diplomat to the Foreign Office for an official dressing down. The council was due to meet on the issue last night.

The UK mission to Moscow came amid deepening outrage over the massacre which the head of the UN observer mission in Syria, Major-General Robert Mood, also warned would fan the flames of instability and "may lead the country to civil war".

As violence continued in Syria yesterday, the Houla massacre has already stretched the credibility of the UN mission in Syria, with the Free Syrian Army issuing a statement saying that the deal was "going to hell" unless there was concerted international intervention. Before departing for Moscow, Hague held talks with Kofi Annan, He said there was a "good case" for increasing the 300-strong UN observer mission, but stressed that time was now running out for the six-point plan, announced in April.

"I've discussed with him [Annan] the urgency of getting a political process going in Syria which is his objective before time runs out," he added, "Time will run out before too long on that."

As the groundswell of Western condemnation grew - and Russia's deputy foreign minister described the events as "tragic" and called for an assessment by the UN - Syria "categorically" denied responsibility for the killings, blaming "terrorists" for the incident. "Women, children and old men were shot dead. This is not the hallmark of the heroic Syrian army," a Syrian foreign ministry spokesperson said in Damascus, who claimed that Syria was being subjected to a "tsunami of lies".

A British diplomatic source dismissed the denials, describing them as a transparent and "concerning" attempt to "seek impunity and lay the blame on others".

Hague said that it was still too early to discuss military or other interventions in Syria. "If we come to the point where the Annan plan has clearly failed, Britain will be arguing for a stronger response from the world, from the United Nations Security Council, increasing our support to the opposition, imposing further sanctions and measures on the Syrian regime," he said.

In Washington, the Obama administration condemned the Houla massacre as the work of the Assad regime, pledging that the "rule by murder" must come to an end. The White House is reported to be renewing pressure on the Russian president, Vladimir Putin, to back a deal that would ease out the Syrian president, Bashar al-Assad, in a fix similar to that brokered in Yemen.