Prime Minister David Cameron is making the case to Parliament for the UK to join US-led air strikes on Islamic State (IS) in Iraq. The Tories, Liberal Democrats and Labour all back action, which the coalition says is legal because it was requested by the Iraqi government. Defence Secretary Michael Fallon has said the campaign could be a “long haul” of “two to three years”. IS has seized large parts of Iraq and Syria in recent months. The group, also known as Isis or Isil, has used tactics that have included beheadings of soldiers, Western journalists and aid workers. It could have as many as 31,000 fighters in Iraq and Syria, according to the CIA. Parliament, which has been recalled to discuss military action in Iraq, is due to vote on UK involvement at about 17.30 BST following a seven-hour debate. The UK is not proposing any involvement in air strikes on Syria. On Thursday, about 250 people protested outside the gates of Downing Street against the possibility of military action in Iraq. Some MPs also oppose the military action. Labour’s Diane Abbott, Jeremy Corbyn and John McDonnell signed aletter to the Guardian which said bombing Iraq would “only exacerbate the situation”. “We urge the government to rule out any further military action in Iraq or Syria,” they said. The government does not have to seek the approval of MPs to commence military action, but it has become customary to do so since this first happened over the Iraq war in 2003. –BBC Online