Conservative former Foreign Office Minister Alistair Burt says the Islamic world is "deeply upset" at the group being identified as 'Islamic State', and tells MPs "we must be sensitive of this".

Former Foreign Office minister and Labour peer Baroness Symons of Vernham Dean says she does not doubt that IS represents a threat to UK citizens at home and abroad. Like other speakers, she questions whether air strikes can succeed without ground troops and without some Syrian involvement.

The Times' Ann Treneman ‏tweets, external: Three brilliant speeches: Pat McFadden, George Galloway and Adam Holloway follow each other, each rivetting in own way

The US is leading a coalition of forces in air strikes on the IS and other Jihadi militant groups in Iraq and Syria. Aircraft and missiles likely to be used by Britain, the US and their allies include the Tornado and the F-22 Raptor.

Labour MP Ian Austin has just tweeted, external: And by contrast, George Galloway just made one of worst speeches I've heard. Claimed ISIL victims quiesced in their persecution. Disgrace.

Respect MP George Galloway - who opposed the 2003 Iraq war and was expelled from the Labour Party over his outspoken comments on the war - says the public are saying a "million 'I told you so's'" across the country.

He says IS is "an imaginary army" with only 10,000 to 20,000 fighters - but it successfully holds the territory it does because it has the support of the population, made possible from past "Western occupation".

Labour MP Ian Austin intervenes in his speech to label his comments "a disgrace". But Mr Galloway insists the problem will not be solved by bombing - and predicts that extremism "will be made worse" by Western intervention.

Mr Galloway is repeatedly challenged by MPs to offer his solution - prompting Mr Galloway to say that those already fighting IS must be equipped with the weapons they need, including the Kurdish fighters. He also says Turkey and Saudi Arabia should be doing more.

"The last people that should be returning to the scene of their former crimes is Britain, France and the United States of America," the Bradford West MP concludes.

Former defence secretary Labour's Lord Hutton of Furness says "we should do what we need to do to win" and not rule out the deployment of UK ground forces.

Mark D'Arcy
Parliamentary correspondent

Iraq war era Attorney general Lord Goldsmith tells peers a case can be made for the use of armed force in Syria, too, under the right of self defence and collective self defence - and he adds "respectfully" that his (ie Labour's) front bench should take note of that.

The motion on IS does not go far enough and is only a "snapshot" of what will be required, opines Conservative Andrew Mitchell - a former government chief whip and ex-international development secretary.

He believes the Commons will, at some point in the future, have to discuss possible UK involvement in air strikes against IS in Syria.

Labour MP Pat McFadden says jihadists are responsible for their own actions and ideology - and says it is a "fundamental mistake" to think that the UK is responsible for violent jihadism. "We cannot say this loudly or clearly enough," he tells MPs.

The Wolverhampton South East MP indicates he will vote in favour of the motion - but asks why it is right to pursue action in Iraq, and not Syria. "Isn't it the case that the motion before us is actually a reflection of where the country stands right now: somewhat limited in its confidence, overburdened by past events, looking too much in the rear view mirror?"

US air strikes destroy four Islamic State tanks near Syrian town of Deir al-Zour, Pentagon says.

Julie Davis in Kent says: "What part of 'global threat' do people not understand….this is not just a decision to jump into conflict for the sake of it, ISIL present a risk to GLOBAL security and we must act!"

Crossbencher Lord Dannatt, a former Chief of the General Staff, says we are "left no option but to take some action".

He advises that "we've been slow to take action", the momentum is with Islamic State and it is "realistic" that military involvement could last for many years. He argues that if air strikes are not enough we should not confine ourselves to measures within Iraqi borders but consider coordinating with Syria and Assad.

The DUP's Westminster leader, Nigel Dodds, underlines the party's support for the motion.

To reject the Iraq government's invitation for assistance "would send a disastrous signal that the UK does not stand by its friends, by its allies, in times of trouble" and that it is prepared to "ignore the barbarism" of IS, he says.

Another DUP MP, William McCrea, adds that the UK "cannot stand idly by and allow Islamic fanatics to terrorise innocent people in Iraq".

Craig in Wirral says: "Even though killing anyone is wrong, sometimes you can't just turn the other cheek and get on with things. In this case we should be bombing ISIS militants. I find it ridiculous that Britain always has to wait for ages until they eventually follow America in these matters."

Nick Robinson
Political editor

A small number of British troops could return to Iraq if the Commons votes for British military action against IS forces tonight although not in a combat role. Downing Street says they would be used to guide air strikes, in a humanitarian role and, possibly, to train Iraqi and peshmerga forces (although this may take place in neighbouring countries).

The government would not extend military action in Syria without a Commons vote unless there is an urgent humanitarian need to do so, the prime minister's official spokesman has said, pointing out that Mr Cameron has pursued a "very deliberate and measured approach and the PM been determined to keep consensus".

Labour's Lord Falconer of Thoroton, a Lord Chancellor under Tony Blair, says "we should stand up to ISIL by using force...there is no other sensible or just option" and that he has "no doubt" that this course of action is legal.

PoliticsHome editor Paul Waugh tweets, external PM's spokesman asked to define humanitarian trigger for action before Parly vote, cites example of Benghazi: "direct threat of large scale loss of life"

Sir Nicholas concludes his brief remarks by wishing good luck and safe return to the UK's RAF Tornado pilots.

Senior Conservative MP Sir Nicholas Soames applauds the "tone and measure" of the prime minister's speech.

He says the government has learned the lessons of successive failures in UK foreign policy towards the Middle East - and describes diplomatic efforts as "magnificent". He says it should be stressed that this "is not the West's fight" and that the UK is acting in support of an Arab coalition.