Image source, Reuters

This is a feature from yesterday, but it's worth having a read given that the PM's claim of there being 70,000 moderate anti-IS forces in Syria who could form the ground troops to take on IS is likely to feature heavily in the debate. Sceptical MPs doubt whether the number is as high as said, and whether the fighters could form a cohesive force.

Image source, Reuters

Syria's president Bashar al-Assad says Russia's involvement in his country's war has led to significant changes, including the "shrinking" of the Islamic State (IS) group.

Russia launched air strikes in late September in support of Mr Assad, Moscow's ally.

Mr Assad told Czech television that US air strikes on Syria had not slowed IS, but that Russian bombing was doing so.

He also condemned the recent shooting down of a Russian warplane by Turkey.

Read more.

Image source, PA

In other news, firearms officers might have to "walk over casualties" in the event of a Paris-style UK attack to deal with the threat, a senior officer has said.

Metropolitan Police Assistant Commissioner Patricia Gallan said officers would "go forward" to confront gunmen in a marauding attack.

She was speaking after an exercise to test the way armed officers would deal with an incident in a shopping centre.

This routine training was arranged before the Paris attacks.

More here.

The shadow minister said he was "convinced" that supporting military action against IS targets in Syria "is the right decision to make".

He said the decision for Labour MPs was "not about whether we support David Cameron" but about the "safety of our country and its people".

James Landale
Deputy political editor

Image source, AFP/Getty Images

It is supposed to be an MP's gravest duty, to decide whether to send Armed Forces in harms way.

And yet it is not really their duty at all. Parliament has no constitutional or legal role in the deployment of the military.

Prime ministers have all the prerogative powers they need to do it by themselves on behalf of the Crown. And they do.

Tony Blair sent troops to Helmand province without a single vote. But Mr Blair did give Parliament a say over invading Iraq in 2003 and that established a precedent which has now become a convention.

In recent days MPs have been briefed by the security services. They have consulted their local parties. And they have agonised on social media.

But tonight is decision time and for once Parliament really is sovereign.

Shadow defence secretary Maria Eagle tells the BBC's Norman Smith that more clarity is needed from David Cameron on the 70,000 troops figure, to convince MPs who have doubts.

Ms Eagle - who will be backing air strikes in tonight's vote - says she reached her decision through "calm consideration" and "serious thought", adding that the UK has an "obligation" to defend its citizens and way of life.

But she says David Cameron's remarks about "terrorist sympathisers" hasn't helped, and claims the prime minister has "demeaned his office".

BBC News Channel

BBC assistant political editor Norman Smith says the government's claim that there are 70,000 moderate anti-IS troops who could fight the extremist group on the ground is the "Achilles heel" in David Cameron’s argument, with a lot of MPs sceptical about the number and effectiveness of those fighters.

Smith gets the sense that in the past 24 hours opponents of air strikes have got "a little bit more oomph" behind them on this argument, he adds - and says this been compounded by the PM's remarks last night about opponents of military action being “terrorist sympathisers”.

BBC Monitoring

The German press sees the Syria vote in the context of British politics. The liberal Sueddeutsche Zeitung flags it up in the "what will be important" section of its website as Britain's "longest day".

It highlights a dispatch from London by Christian Zaschke, saying that David Cameron "moved fast over Labour's lack of discipline" in order to erase the memory of "his worst defeat as prime minister" when he lost the vote to bomb Syria in 2013.

The more conservative Frankfurter Allgemeine Zeitung notes that critics of bombing fear the "failure of the Iraq and Afghanistan wars will be repeated, and the terrorist threat in the UK will increase". Left-wing tageszeitung's UK analyst, Ralf Sotscheck, is hostile to Mr Cameron's plans, saying he "doesn't want to lag in the struggle for influence in the Middle East, disregarding previous experience in Iraq, Afghanistan and Libya". Mr Sotscheck says the impact on Syria civilians "plays no role in Cameron's thinking", and warns that Labour Leader Jeremy Corbyn's opposition to bombing reflects a "prevalent deep mistrust among the British public".