Assad using chemical weapons: PM
David Cameron has said there is credible evidence of "multiple attacks" using chemical weapons by Syrian President Bashar Assad's regime.
The Prime Minister said the UK believes the "scale of use is sanctioned and ordered by the Assad regime" but also indicated that al Qaida-linked elements in the opposition movement had also attempted to acquire chemical weapons for probable use in Syria.
He restated the Government's position that no decision had been taken to arm moderate rebels opposed to Assad, but added that he was a "brutal dictator who is using chemical weapons under our nose".
Mr Cameron has backed Washington's "candid assessment" that the Syrian regime has used chemical weapons. US president Barack Obama has approved arming the Syrian rebels for the first time in response to the development, according to officials.
Speaking in the garden at 10 Downing Street, Mr Cameron said the US view was "consistent with what we have already said" about chemical weapons use. He said: "There is credible evidence of multiple attacks using chemical weapons in Syria, including the use of the abhorrent agent sarin."
British experts at the Porton Down chemical warfare testing establishment have been involved in the assessment of samples taken from two sites in Syria, the Prime Minister said.
"We believe that the scale of use is sanctioned and ordered by the Assad regime," he said. "We haven't seen any credible reporting of chemical weapons use by the Syrian opposition. However, we assess that elements affiliated to al Qaida in the region have attempted to acquire chemical weapons for probable use in Syria."
Mr Cameron said he had to "choose my words carefully" as he revealed the information presented to him by the Joint Intelligence Committee. He said: "I always choose my words on this subject very carefully because of the issues there have been in the past. I think it is right that the Americans have said what they have said and I wanted to back that up with the information and the involvement that we have had in that assessment."
The UK led calls for the European Union's arms embargo on Syria to be lifted, and Mr Cameron said evidence of chemical weapons use by Assad justified that move.
Mr Cameron said: "We have made no decision to arm the opposition, but it was right to lift the arms embargo. The information about chemical weapons further shows the folly of having some embargo that gives some sort of almost moral equivalence to President Assad and to the legitimate opposition. We will continue to support, train and assist and work with the opposition."