UK Prime Minister David Cameron has admitted "there is no 100% certainty about who is responsible" for the chemical weapons attack in Syria as he made his case in the Commons for possible future military action.
The Prime Minister told MPs there is not "one smoking piece of intelligence" but insisted he was convinced by the evidence that Bashar Assad's regime was responsible.
Labour has confirmed it will vote against the Government's motion tonight after the Government published legal advice supporting action.
Evidence from the Joint Intelligence Committee found that a chemical weapons attack did occur in Damascus last week and it is "highly likely" that Bashar Assad's regime was responsible.
But Labour wants "compelling evidence" before committing its support for the Government's approach.
Mr Cameron said: "In the end there is no 100% certainty about who is responsible. You have to make a judgment.
"There is also no 100% certainty about what path of action might succeed or fail but I think we can be as certain as possible that when we have a regime that has used chemical weapons on 14 occasions, that is most likely responsible for this large scale attack, that if nothing is done it will conclude that it can use these weapons again and again and on a larger scale and with impunity.
"When people talk about escalation to me the biggest danger of escalation is if the world community, not just Britain but America and others, stand back and do nothing because I think Assad will draw very clear conclusions from that."