The Islamic State of Iraq and the Levant (ISIL) is proscribed as a terrorist organisation by the United Kingdom. British citizens have fought as members of the group, and there has been political debate on how to punish them. On 26 September 2014, Parliament voted to begin Royal Air Force airstrikes against ISIL in northern Iraq at the request of the Iraqi government,[1] which began four days later, using Tornado GR4 jets.[2] On 2 December 2015, the UK Parliament authorised an extension to the Royal Air Force airstrike campaign, joining the US-led international coalition against ISIL in Syria.[3] Hours after the vote, Royal Air Force Tornado jets began bombing ISIL-controlled oilfields.[4]