As two British Islamic State jihadists are killed by an RAF drone strike in Syria, here is a timeline of Britain’s involvement in Syria since 2013.

August 2013 A Syrian victim who allegedly suffered a chemical attack at Khan al-Assal village Following the confirmed use of chemical weapons against civilians near Damascus, Prime Minister David Cameron announces Parliament is being recalled to discuss the UK’s response to Syria.

August 2013 After eight hours of parliamentary debate, MPs reject the government’s motion in support of military action in Syria. Following the vote, Mr Miliband said: “Military intervention is now off the agenda for Britain. There would have been nothing worse than intervention without full international support.”

September 2013 Former party leader Ed Miliband is criticised for hardening his position over Syria by saying that Labour would only support military action against the Assad regime if Britain’s national security was threatened. A concerned Labour MP said: “I am very worried that this could lead us to a position where Britain is not able to mount a military response if needed.”

September 2014 The Prime Minister says there is a “strong case” for UK military intervention in Syria and that it would be lawful on the grounds of intervening to prevent a humanitarian catastrophe. He added the government would seek Parliamentary approval for the extension of air strikes against IS extremists in Iraq to Syria.

February 2015 The UK said that no decision had been made about how it would be involved in the fight against IS, but that it would play a "leading role".

June 2015 A man prays after laying flowers on Marhaba beach where 38 people were killed Britain moved a step closer to bombing IS targets in Syria as Labour said it would consider backing any military response to the Tunisian beach shootings in which 30 Britons were killed by gunman Seifeddine Rezgui.

July 2015 British military pilots conduct air strikes over Syria for first time British ministers were accused of deceiving the public after it emerged that at least three Royal Navy pilots had been killing IS fighters in Syria, even though MPs voted against military action there.