Britain announced it would double support to Syria´s fractured opposition forces amid reports that almost the entire 50,000 strong Christian population of Homs had been driven out by fighting.

William Hague, the Foreign Secretary, told the Lord Mayor´s Easter banquet in the City, that £500,000 would be set aside to provide "non- lethal" assistance to hard-pressed opponents of the Assad regime.

Britain has already provided £450,000 to the opposition since last year but the new resources will be used to extend the scope of support to include satellite communications equipment, training schemes and back office facilities for the opposition. Britain sent an expert mission to the region last month to help document the atrocities that have taken place, so that regime figures will ultimately be held to account.

The scale of violence reached an unrivalled peak in Homs where the number of Christian´s left in the ancient city has fallen below 1,000. As a major government offensive against Baba Amr and other rebel-held areas of Homs got under way in early February, many Christians left the city because of the intensity of the fighting.

One priest from the district of Hamidiya, who fled to Lebanon seven weeks ago, said friends who remained in the city had spoken of a growing "atmosphere of fear".

"Some Christians who tried to escape a week ago were stopped from leaving by the rebels and were instead forced to go to a mosque to act as shields," he said. "They thought that, because Christians support Assad, the government would not attack them."

Church leaders have accused Muslim neighbours of turning on the Christians, who have fled to villages and towns around the city, as well as into Lebanon.

"The people we are helping are very afraid," Bishop Antoine Audo of Aleppo said. "The Christians don´t know what their future will hold. They are afraid they will not get their homes back.

However Abou Salaam, a Jesuit priest in the city, said that Muslim imams had held meetings with the remaining Christians to reassure them they were safe in the city.

Despite the broad public respect they enjoy from the rebel leaders, many Christians fear that they will remain vulnerable. About one in 10 of Syria´s 20 million population is Christian.

"There were rumours of extremists coming to Homs from other Muslim countries to fight with the rebels," he said. "We don´t know if it was true, but it frightened many people."

He added: "The Christians are caught in the middle. We are victims of both sides."

Efforts to stop Syria´s descent into civil war reached a decisive juncture with the launch of Mr Annan´s peace initiative, which has the support of Russia and China as well as the West and the Arab League.

Officials said that the opposition needed to come together as a viable opponent and a potential alternative centre of power to President Assad, if, as hoped, he is eased out of power.

"The behaviour of the Assad regime so far is as futile as it is morally indefensible," Mr Hague said. "They have now said they will accept Kofi Annan´s plan to end the violence and start a political transition.

"President Assad and his allies ... must be left in no doubt that if there is not a political transition that reflects the will of the people, then they will be shunned by the international community and we will close every door to them. They will face still more sanctions. Their assets will remain frozen. Their travel to Europe and many other nations will always be banned, as will the travel of their families. And they will be pursued by mechanisms of justice and held to account."

With at least 26 killed in continuing government offensives two days after the Syrian leader accepted Mr Annan´s proposals. Mr Assad set out conditions of his own for a ceasefire.

The Annan plan must also get a commitment from armed groups to cease their "terrorist acts" against the government, according to the state news agency Thursday.

"It is necessary to get a commitment from other parties for armed groups to stop their terrorist acts, to withdraw the weapons of these groups ... and for them to stop ... kidnapping innocent civilians, massacres and the destruction of private and public infrastructure,"

Julien Barnes-Dacey, a Syrian analyst at the European Council on Foreign Relations, said champions of the Syrian opposition had been forced to accept that diplomatic efforts to oust Assad would prevail over military options.

"The Annan plan is the only game in town for the moment," he said. "Outside intervention is impossible for diplomacy is the only way forward. Therefore there is a need to build a stronger opposition to take part in the political process."

At least one million Syrians need humanitarian assistance, a UN spokesman said Thursday at the end of an assessment mission to the country international experts. (© Copyright of Telegraph Media Group Limited 2012. 03/30/12)