Britain cannot rule out having to send in ground troops to do "the dirty work" in the fight against Islamic State (IS) because air power alone is not enough to defeat them, a Tory MP and ex-army officer has said.
In the first admission by a British politician that air strikes and drones could not be enough to "degrade and destroy" IS - as Cameron has insisted Britain will do - Tory MP Bob Stewart, who sits on parliament's defence committee, said the government could not rule out ever sending in the infantry.
But Stewart said he hoped it would not fall to Britain to do it this time, and called on countries in the region to step up.
The prospect of ground troops to fight IS fills British politicians with dread, as memories of the Iraq War are still raw and divisive.
When Barack Obama described his strategy to fight IS last week, he ruled out ground troops saying: This is not the equivalent of the Iraq war."
Speaking on Radio 4's Today Programme this morning, Mr Stewart said: "What we want to do is build a coalition of people, local countries, who will actually go in on the ground.
"Because one of the intentions may well be to draw us in so we are pulled in on the ground and then IS can present it as the Islamic world versus the evil West.
"The countries in the region should sort it out. Wouldn't it be wonderful if just for once Iran and the Saudis cooperated across the schism that obviously exists between their two branches of religion because the threat to both those countries is huge?"
He also said that IS would "probably" be able to sustain itself unless someone goes in on the ground because of its apparent access to banks and oil.
"You can't win this from the air - someone has got to go and do the dirty work," he went on.
"I don't want it to be us this time. The Americans don't want it to be them. Let's just hope we can find sufficient forces on the ground with the ability."
Interviewed on the same programme, Labour MP Ann Clwyd, who sits on the foreign affairs committee, said: "The group won't be defeated, clearly, as long as it can rampage through Syria with impunity."
Meanwhile, London mayor Boris Johnson has joined the chorus of British politicians backing British military action against IS.
"We may not be able to bring peace at a stroke, but David Cameron is absolutely correct to want to use British forces to help bring the killers of David Haines to justice," he wrote in his Daily Telegraph column today.
"For all our occasional spasms of self-doubt, we are one of the great powers of the world with some of the finest armed forces.
"We would be mad not to use our defence capability, where we can, to make the world a better place."