Jeremy Corbyn has written a letter to Labour MPs saying he “cannot support” David Cameron’s plans for British air strikes on Isis in Syria.

The Leader of the Opposition wrote that although he was horrified by the “despicable” Paris attacks and was determined to see the extremist group defeated, he did not believe the Prime Minister made a convincing case.

“In my view, the Prime Minister has been unable to explain the contribution of additional UK bombing to a comprehensive negotiated political settlement of the Syrian civil war, or its likely impact on the threat of terrorist attacks in the UK,” Mr Corbyn wrote.

PM: Bombing Syria is necessary

“For these and other reasons, I do not believe the Prime Minister's current proposal for air strikes in Syria will protect our security and therefore cannot support it.”

The shadow cabinet debated the issue at a meeting today and will convene today on Monday to attempt to reach a consensus that has so far evaded members.

Labour frontbenchers are reported to be deeply divided on the prospect of extending RAF air strikes from Iraq into Syria in the wake of calls for a wider international push against Isis in the wake of the Paris attacks.

Mr Corbyn said his first priority was “the security of Britain and the safety of the British people” but claimed the Government’s proposed strategy was not “coherent” or adequately co-ordinated through the UN.

Jeremy Corbyn responds to David Cameron's seven-point plan to bomb Syria (PA)

He also questioned what “credible and acceptable” ground forces could hold territory freed from Isis by an intensified air campaign.

His comments came after a Russian pilot was killed by “moderate” anti-Assad rebels loosely affiliated to the US-backed Free Syrian Army.

Mr Corbyn’s comments clashed with those made by his shadow Foreign Secretary, Hilary Benn, who said the Prime Minster had set out a “compelling argument” in favour of intervention.

Speaking following today’s shadow cabinet meeting , Mr Benn said: “I think we have heard a compelling argument – both because of the threat to the United Kingdom and also because we are right to have been taking the action that we have in Iraq to support the Iraqi government in trying to repel the invasion from Isil and we’ve seen recently the success of the Peshmerga forces with support from the air in pushing Isil out of Sinjar.

In pictures: Syria air strikes (2014) Show all 20 1 /20 In pictures: Syria air strikes (2014) In pictures: Syria air strikes (2014) Syria Syrian citizens check a damaged house that targeted by the coalition airstrikes, in the village of Kfar Derian, a base for the al-Qaida-linked Nusra Front, a rival of the Isis group, between the northern province of Aleppo and Idlib In pictures: Syria air strikes (2014) Syria A Syrian boy (L) looking at a destroyed car that activists say was targeted by the coalition airstrikes, in the village of Kfar Derian, a base for the al-Qaida-linked Nusra Front, a rival of the Islamic State group, between the northern province of Aleppo and Idlib In pictures: Syria air strikes (2014) Syria Parts of a missile that activists say was fired by coalition airstrikes, in the village of Kfar Derian, a base for the al-Qaida-linked Nusra Front, a rival of the Isis group, between the northern province of Aleppo and Idlib In pictures: Syria air strikes (2014) Syria Tthe guided-missile destroyer USS Arleigh Burke (DDG 51) launching Tomahawk cruise missiles against Isis targets In pictures: Syria air strikes (2014) Syria The USS Arleigh Burke (DDG 51) launches a Tomahawk cruise missiles in the Red Sea, to conduct strike missions against Isis group targets in Syria In pictures: Syria air strikes (2014) Syria The guided-missile cruiser USS Philippine Sea (CG 58) launching a Tomahawk cruise missile against Isis targets in Syria, as seen from the aircraft carrier USS George H.W. Bush (CVN 77) in the Arabian Gulf In pictures: Syria air strikes (2014) Syria US navy sailors standing watch on the bridge while Tomahawk cruise missiles are launched against Isis targets in Syria, aboard the guided-missile cruiser USS Philippine Sea (CG 58), in the Arabian Gulf In pictures: Syria air strikes (2014) Syria An F/A-18C Hornet, attached to Strike Fighter Squadron (VFA) 87 prepares to launch from the flight deck of the aircraft carrier USS George H.W. Bush (CVN 77) in the Arabian Gulf, to conduct strike missions against Isis group targets AFP/Robert Burck In pictures: Syria air strikes (2014) Syria The US-led airstrikes in Syria against Isis targets in and around the city of Raqqa In pictures: Syria air strikes (2014) Syria A fighter from the Isis group holds a piece of what the IS is saying is a US drone that crashed into a communications tower in the Syrian city of Raqqa In pictures: Syria air strikes (2014) Syria Fighters from the Isis organisation pray at the spot where the jihadist group said a US drone crashed into a communications tower in the Syrian city of Raqqa In pictures: Syria air strikes (2014) Syria Fighters from the Isis group load a van with parts that they said was a US drone that crashed into a communications tower in the Syrian city of Raqqa In pictures: Syria air strikes (2014) Syria Fighters from the Isis group load a van with parts that they said was a US drone that crashed into a communications tower in Raqqa In pictures: Syria air strikes (2014) Syria Fighters from the Isis group gesture as they load a van with parts that they said was a US drone that crashed into a communications tower in Raqqa. A US-led coalition on carried out its first air strikes and missile attacks against jihadist positions in Syria, with Damascus saying it had been informed by Washington before the operation began In pictures: Syria air strikes (2014) Syria A Syrian man rides his bike past a communications tower that was destroyed after a US drone crashed into it, according to fighters with the Isis group, in the Syrian city of Raqqa In pictures: Syria air strikes (2014) Syria People inspect a shop damaged after what Isis militants say was a U.S. drone crashed into a communication station nearby in Raqqa In pictures: Syria air strikes (2014) Syria A man holds the remains of what Isis militants say was a U.S. drone which crashed in Raqqa In pictures: Syria air strikes (2014) Syria Resident gather in the back of a van the remains of what Isis militants say was a drone which crashed in Raqqa In pictures: Syria air strikes (2014) Syria A man inspects the remains of what Isismilitants say was a U.S. drone which crashed into a communication tower in Raqqa In pictures: Syria air strikes (2014) Syria A man inspects the remains of what Isis militants say was a U.S. drone which crashed in Raqqa

“We’re also trying to make life difficult for Isil in Syria and I think I think there’s a very strong case for us playing our full part in doing that given that we are currently flying missions, providing intelligence and refuelling to others who are participating.

“I think our allies look to us, particularly the French after the grievous blow they have suffered in Paris, and they want to feel that we are with them in solidarity and I think we should be.”

Addressing the House of Commons this morning, Mr Cameron warned that the jihadist group views the UK as a “top tier” target.