David Cameron has appealed for MPs to back British airstrikes against Islamic State (IS) in Syria, asking: "If not now, when?"
The Prime Minister said the UK could not afford to "stand aside" from the fight and it was "morally" unacceptable to leave the US, France and other allies to carry the burden.
He insisted there was strong legal justification for extending the current military action in Iraq, on grounds of self-defence and the recent UN Security Council resolution.
In a statement to the Commons, Mr Cameron admitted that IS - also known as Isis, Isil and Daesh - could not be defeated by airstrikes alone. But he argued it was a key part of a wider "comprehensive" strategy to deal with the threat.