A day after RAF fighter jets joined the mission to beat Islamic State in Iraq, David Cameron has said he also wants to make the case for targeting Syria.

 

In an interview with the Sunday Times, the Prime Minister revealed he would argue that targeting Syria is both legal and appropriate.

 

"There are complications but there aren't legal difficulties," he said.

 

The RAF carried out two sorties over Iraq on Saturday after Parliament gave the green light for airstrikes on IS militants.

 

In both missions the Tornado GR4 fighter bombers did not use their weapons, although the Ministry of Defence said "invaluable intelligence" had been gathered using the planes' surveillance equipment.

 

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The jets, who fly in pairs, returned to their base at RAF Akrotiri in Cyprus at the end of their hours-long missions with their weapons payload intact.

 

Mr Cameron said he would respond to the challenge thrown down by Ed Miliband to seek a UN resolution supporting attacks in Syria, if only to show that his request is impossible.

 

"We have to demonstrate to people that we'd like a UN security council resolution but it's very difficult to get one and to demonstrate that what we propose is legal. Attempts have been made but there's the existence of a Russian veto."

 

His comments come as two former senior military commanders have questioned Mr Cameron's policy of isolated air attacks.

 

Lord Richards of Herstmonceux, a former head of the UK military who stepped down as chief of the defence staff last year, said a campaign involving ground troops would be needed to crush IS.

 

A map showing the location of RAF Akrotiri in relation to Iraq and Syria.

"Ultimately you need a land army to achieve the objectives we've set ourselves - all air will do is destroy elements of Isis, it won't achieve our strategic goal," he told the Sunday Times.

 

"The only way to defeat Isis is to take back land they are occupying which means a conventional military operation. The only way to do it effectively is to use western armies but I understand the political resistance."

 

Richard Williams, a former commanding officer of the SAS who served in Bosnia, Iraq and Afghanistan, wrote in the Independent on Sunday the deployment of RAF bombers was a "military sugar rush" that "risks looking fearful and half-cocked".

 

Royal Air Force Tornado GR4 aircrew prepare to depart RAF Akrotiri in Cyprus. Pic: MoD.

RAF crew at the base on Saturday morning

Lieutenant Colonel Williams said the sending in of RAF bombers had "taken on a military and political significance out of all proportion to their real military value".

 

He wrote: "They provide us and our leaders, desperate to do something, with a military sugar rush, to be followed inevitably in six months' time with the 'war-downer' reality that things are not going as we wish them to, and that the long-term costs of our involvement are escalating, in ways that will need to be explained, or hidden, during a general election."

 

Ministers had cautioned not to expect a campaign of "shock and awe" and that after weeks of US airstrikes in the area it could take time to identify new targets.

 

Royal Air Force Tornado GR4 aircrew prepare to depart RAF Akrotiri in Cyprus.

A member of the aircrew prepares to depart on the first mission. Pic: MOD

Mr Cameron insisted the involvement of RAF combat aircraft showed Britain was there to "play our part" in the international coalition being assembled against IS.

 

"We are one part of a large international coalition," the Prime Minister said during a visit to Didcot, Oxfordshire, ahead of the Conservative Party conference.

 

"But the crucial part of that coalition is that it is led by the Iraqi government, the legitimate government of Iraq, and its security forces. We are there to play our part and help deal with this appalling terrorist organisation."