PM makes Commons statement saying UK cannot afford to stand aside and let other countries carry the burden – and asks: ‘If not now, when?’David Cameron has urged MPs to back UK airstrikes against Islamic State in Syria, saying that the terrorist organisation is using the sanctuary of northern Syria to launch plots with deadly intent against the British people.In a statement to the Commons the prime minister appealed for MPs to back airstrikes in Syria, asking: “If not now, when?” Cameron 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.