The Foreign Secretary on Tuesday demanded an end to the violent repression by the Syrian security forces against pro-democracy supporters, saying that they may face sanctions.
"I condemn utterly any violence and killings perpetrated by the Syrian security forces against civilians who are expressing their views in peaceful protests,” said William Hague in a statement.
According to activists, over 20 people were killed on Monday by government forces in Syria. They say that at least 350 people have been killed in the last five weeks as demonstrators have joined the wave of protests sweeping North Africa.
Many of the protesters are demanding that President Bashar al-Assad step down, but have met with increasing pressure from authorities in recent days.
Mr Hague said: “President Assad should order his authorities to show restraint and to respond to the legitimate demands of his people with immediate and genuine reform, not with brutal repression.”
He said that the UK and its partners were considering the use of "further measures" against Damascus, including sanctions.
Mr Hague said Syria was "at a fork in the road", in a statement to the House of Commons.
"Its government can still choose to bring about the radical reform which alone can bring about peace and stability … or it can choose ever more violent repression," he said.
"If it does so, we will work with our European partners and others to take measures including sanctions that will have an impact on the regime."
The Foreign Office has advised British nationals to leave Syria. “This is because of increasingly violent disturbances in urban centres across the country, including the capital Damascus, and reports of live gunfire by security forces resulting in an increasing number of deaths,” said a statement on the Foreign Office website.