David Cameron tells House of Commons Britain 'must take on evil of IS before they attack us'

Read more: 72% of Scots oppose Syria air strikes 

Starting that debate Mr Cameron insisted he had "respect" for those who will vote 'no' as he sought to play down a row over comments he made to Tory backbenchers last night, when he reportedly urged them not to vote with a "bunch of terrorist sympathisers".

But he warned MPs: "Isil have brutally murdered British hostages. They have inspired the worst terrorist attack against British people since 7/7 on the beaches of Tunisia.

"And they have plotted atrocity after atrocity on the streets here at home.

Read more: Ian Bell on the 'hellish war' that awaits  

"Since November last year, our security services have foiled no fewer than seven different plots against our people. So this threat is very real.

"The question is this: do we work with our allies to degrade and destroy this threat and do we go after these terrorists in their heartlands, from where they are plotting to kill British people.

"Or do we sit back and wait for them to attack us?"

Read more: Mike Settle's analysis 

Mr Cameron promised to take dozens of interventions as he made his case for war ahead of the crunch vote.

He told MPs: "I am not pretending the answers are simple. The situation in Syria is incredibly complex - I am not overstating the contribution that our incredible servicemen and women can make.

"Nor am I ignoring the risks of military action, nor am I pretending military action is any more than one part of the answer - I am absolutely clear we must pursue a comprehensive strategy that also includes, political, diplomatic and humanitarian action.

Read more: Salmond demands apology from PM 

"I know the long-term solution in Syria, as in Iraq, must ultimately be a government that represents all of its people. One that can work with us to defeat the evil organisation of Isil for good.

"But not withstanding all of this, there is a simple question at the heart of the debate today."

Seeking to head off complaints about his attack on Labour leader Jeremy Corbyn, Mr Cameron told MPs: "The question before the House today is how we keep the British people safe from the threat posed by Isil.

"Let me be clear from the outset. This is not about whether we want to fight terrorism, it's about how best we do that. I respect governments of all political colours in this country have had to fight terrorism and had to take the people with them as they do so.

"I respect people have come to a different view from the Government than the one I will set out today and those who vote accordingly."

Former Labour minister Caroline Flint was the first to call on Mr Cameron to retract his remark, intervening to say: "Will you apologise for the remarks made?"

Mr Cameron said he could "not have been clearer" in his opening remarks.

John Woodcock said none of his fellow Labour MPs would be forced into making a decision by "threats" from activists or from the Opposition at the despatch box.

The MP for Barrow and Furness rebuked the PM for his language on the issue, adding: "No-one on this side of the House will make a decision based on any such remarks nor will we be threatened from doing what we believe is the right thing, whether those threats come from online activists or indeed from our own despatch box."

Mr Cameron replied: "I completely agree with you. Everyone in this House should make up their mind on the arguments in this House and there's honour in voting for, there's honour in voting against.  

"That is the way this House should operate and that's why I wanted to be absolutely clear at the start of my sentence that this is about how we fight terrorism not whether we fight terrorism."

Mr Cameron reiterated the work of the RAF in Iraq, claiming 30% of territory has been recaptured from IS.

Addressing the controversial issue of which forces may retake IS territory after they are defeated, he stressed that rebel groups are beginning to agree ceasefires with Assad troops in order to fight the terrorists.

The Prime Minister's claim that there are 70,000 moderate Syrian rebels has been hotly disputed, with questions over the veracity of Britain's intelligence remaining for many MPs.

But Mr Cameron insisted: "I think it is important when it comes to our arguments about ground troops, in my discussions with the King of Jordan, he was making the point that in the south of Syria there already is co-operation between of course the Jordanian government and the French and the Americans and the Free Syrian Army, but also there's a growing ceasefire between the regime troops and the Free Syrian Army so they can turn their guns on Isil.

"That is what I have said - this is an Isil first strategy, they are the threat, they are the ones we should be targeting, this is about our national security."

Mr Cameron admitted it would take longer to defeat IS because the coalition was relying on local ground forces to retake territory.

He said: "In time we hope for Syrian ground troops from a transitional regime but all of that takes longer and I think that one of the clear messages that has to come across today is that, yes, we do have a strategy.

"It's a complex picture, it will take time, but we are acting in the right way."

Mr Cameron turned to the term used to describe "this evil death cult", telling MPs it was "time to join our key ally France, the Arab League and other members of the international community in using as frequently as possible the terminology Daesh rather than Isil".

He said: "Frankly, this evil death cult is neither a true representation of Islam nor is it a state."

Labour MP Emily Thornberry (Islington South & Finsbury) intervened to urge Mr Cameron to withdraw his remarks, branding them "offensive" and saying "it is dangerous and it is untrue".

Mr Cameron replied: "I've made my views clear about the importance of all of us fighting terrorism and I think it's time to move on."

On the question of whether acting could increase the risk to Britain's security - "one of the most important questions we have to answer" - he said: "Paris wasn't just different because it was so close to us, or because it was so horrific in scale; Paris was different because it showed the extent of terror planning from Daesh in Syria and the approach of sending people back from Syria to Europe.

"This was, if you like, the head of the snake in Raqqa in action."

He added that it was not surprising, in his view, that the judgment of the chair of the Joint Intelligence Committee and the director-general of the security service is that "the risk of a similar attack in the UK is real and that the UK is already in the top tier of countries on Isil's target list".

He said: "If there is an attack on the UK in the coming weeks or months, there will be those who try to say it's happened because of our air strikes. I do not believe that would be the case. Daesh have been trying to attack us for the last year as we know from the seven different plots that our security services have foiled."

Mr Cameron said 800 people including families and children had been radicalised to "such an extent" that they had travelled to the so-called caliphate, adding: "The House should be under no illusion these terrorists are plotting to kill us and to radicalise our children right now. They attack us because of who we are, not because of what we do."

Mr Cameron stressed to the House the importance of the UK's precision targeting capabilities.

He said: "There is, of course, in the coalition a lot of strike capacity but when it comes to precision strike capability, whether covering Iraq or Syria, last week the whole international coalition had some 26 aircraft available. Eight of those were British Tornados, so typically the UK actually represents between a quarter and a third of the international coalition's precision bombing capability.

"We also have about a quarter of the unmanned strike capability flying in the region.

"So we have a significant proportion of high precision strike capability.

"That's why this decision is so important."

Mr Cameron said US President Barack Obama and French President Francois Hollande had both told him that British planes would make a "real difference in Syria just as they are already doing in Iraq".

He also said it makes "no sense" for the UK to respect the border between Iraq and Syria when Daesh do not.

"We have these capabilities that other members of the coalition want to benefit from and it makes absolutely no sense to stop using these capabilities at a border between Iraq and Syria that Daesh simply do not recognise or respect," he said.

Mr Cameron said there had in fact been a recent incident when Syrian opposition forces needed urgent support against Daesh in Syria and RAF planes were "just eight minutes away" over the border in Iraq.

He said: "No-one else was close but Britain couldn't help so the Syrian opposition forces had to wait 40 minutes in a perilous situation while other coalition forces scrambled.

"That sort of delay, it endangers the lives of those fighting Daesh on the ground and, frankly, does nothing for our reputation with our vital allies."

Mr Cameron also said the UK "cannot wait" for a political settlement in Syria before targeting IS.

He said: "The threat is now. Isil Daesh are planning the attacks now."