The UK's next step in the war on the Islamic State (Isis) will be decided on 2 December when MPs vote on David Cameron's plan to bomb Syria. The parliamentarians will be locked in a 10-hour-long debate in the House of Commons before casting their votes in the lobbies.
The discussion means Prime Minister's Questions (PMQs) has been cancelled and comes after Cameron called for air strikes on IS targets in Syria in the wake of the terror attacks on Paris which left at least 130 people dead. Jeremy Corbyn, a former chair of the Stop the War Coalition, has argued that the prime minister's case for war was unconvincing. But the Labour leader has given his MPs a free vote on the issue after significant pressure from his shadow cabinet.
Some reports have suggested that up to 50 Labour MPs could defy Corbyn and vote for air strikes on IS, while Cameron was given a big boost on the night of 1 December when the eight-strong Liberal Democrats backed his call for action in Syria.
"I believe it is right to support what is a measured, legal and broad-based international effort to tackle the evil regime that has contributed to the hundreds of thousands of desperate refugees, fleeing for their lives," said Tim Farron, the leader of the Liberal Democrats.
"I have seen the refugee crisis for myself both in Calais and in Lesbos. I think we cannot tackle the refugee crisis without working on a plan to end the civil war in Syria. Furthermore, I cannot look those people in the eye without saying that I have done all I can to destroy Isis, to support the Vienna peace process and an effective transition away from the [Bashar al-Assad] regime."
The Democratic Unionist Party (DUP), who have eight MPs in the Commons, also plan to vote alongside the prime minister on the issue. But up to 110 MPs from six different parties are backing an SNP amendment in a bid to block the air strikes.
The vote follows Cameron's defeat in the Commons in 2013 when MPs voted against his proposal to bomb Assad and his forces amid allegations of war crimes levelled at the Syrian ruler. The target has now changed to IS, but concerns have been raised about who the UK will side with during the conflict.
Cameron has claimed that up to 70,000 non-Islamist rebels would fight against Isis but Julian Lewis, the Conservative chairperson of the Defence Committee, questioned the strength of moderate fighters in Syria.
"The suggestion that there are 70,000 non-Islamist credible ground forces I have to say is a revelation to me and I suspect most other members in this house," Lewis said. "Adequate grounds forces, in my view, depend on the participation of the Syrian army."