NICOLA Sturgeon has accused David Cameron of making an “heroic assumption” in suggesting there are as many as 70,000 moderate armed forces in Syria as he considers air strikes against Islamic State.

The First Minister said she would continue to listen to the arguments for bombing the terror group ahead of a possible Commons vote on Wednesday, but remained unpersuaded.

Speaking after a meeting of the British-Irish Council in London, the SNP leader was asked why she continued to oppose extending RAF airstrikes given IS's catalogue of terrorist atrocities and warnings from defence and security chiefs that Britain is now in greater danger if further military action is not taken and that France and the US want the UK to participate in airstrikes.

“We all have to reach our own judgements on these things,” declared the First Minister, noting how David Cameron had “adopted a very good tone” in his Commons statement and had recognised people were confronted by very difficult decisions.

“We all want to defeat IS, we all want to demonstrate solidarity with France and with others who have been victims of terrorist attacks but we cannot in this situation or any other situation get into the realms of doing anything just in the interests of doing something.”

She went on: “We have always said we would listen; we have listened and we will continue to listen between now and the vote in the House of Commons.”

Her comments came as Labour leader Jeremy Corbyn's shadow team were openly split on whether to back Mr Cameron's call as Deputy leader Tom Watson became the latest leading figure to speak out in support of bombing IS. Mr Watson and Shadow foreign secretary Hilary Benn, who said there was a compelling case for air strikes, are both at odds with their leader.

However, the prospect of mass resignations was played down if the shadow cabinet does not agree to give its MPs a free vote at a meeting on Monday.

Ms Sturgeon accepted that the Prime Minister had gone some way in answering some of the outstanding questions on whether or not extending airstrikes was justified but she made clear there remained two key areas where the SNP Government and party had significant concerns: ground troops and reconstruction.

“These are the reasons we are not persuaded and we are not the only ones to express these concerns. The first is on the issue of ground troops.

“Who is on the ground who recaptures and governs the territory IS hopefully is pushed out of? The numbers the PM was citing in the House of Commons perhaps fell into the category of heroic assumptions in terms of the numbers, where these people are, who they are and their capacity to do this job on the ground.

“Many of these moderate Syrian fighters are, of course, under attack by the Russian forces at the moment. Why is it important? It’s important in directing airstrikes to minimise civilian casualties and then in taking the territory. That is not just a minor point but a critical point in terms of the effectiveness of airstrikes.”

Mr Cameron for the first time used the figure of 70,000 moderate armed forces in Syria during his Commons statement on Thursday. No 10 insisted the figure was the product of “robust analysis”.

It accepted that these forces were in different parts of Syria and were not under a unified command but stressed that already in places they had degraded IS’s military capacity.

Ms Sturgeon added: “The second point, which is longer term but still important is the issue of reconstruction. That is where there is a significant lesson to be learned from Iraq and where, the PM, did have something to say. We would like to hear more.”