Cameron is in serious trouble at Westminster after overreaching himself by the claim that there are 70,000 “moderate rebels” willing to take up the ground war with Isis. Quite literally not one single MP believes him. There are those who believe the lie is justified. But even they know it is a lie.

There is a very interesting parallel here with the claims over Iraqi WMD. The 70,000 figure has again been approved by the Joint Intelligence Committee, with a strong push from MI6. But exactly as with Iraqi WMD, there were strong objections from the less “political” Defence Intelligence, and caveats inserted. As the Head of Defence Intelligence, Major-General Michael Laurie, told the Chilcot Inquiry:

“we could find no evidence of planes, missiles or equipment that related to weapons of mass destruction (WMD). It was clear to me that pressure was being applied to the Joint Intelligence Committee and its drafters. Every fact was managed to make the dossier as strong as possible. The final statements in the dossier reached beyond the conclusions intelligence assessments would normally draw from such facts.”

The truth is the military tends to be much more honest about these matters than the spooks. Rather than make the same mistake again, parliamentarians should be calling Laurie’s successor, Air Marshal Philip Osborn, to ask him the truth about the nature, composition and availability of the 70,000. I happen to know that signals of dissent from Osborn’s staff – quite probably with his blessing – are reaching not just me, but many Tory MPs.

Meantime we can ourselves deconstruct the 70,000 figure and work out the various civil service sleights of hand that produced it. We have Cameron’s written response to the Foreign Affairs Committee in which he sets out his case for war. This document is of course extremely carefully written.

The 70,000 figure is at page 18. It does then give the breakdown of who these 70,000 are.

The very first group listed are the Kurds, and they are indeed the best organised and most numerous group. But there is a trick here – the paper includes them in the 70,000, despite going on to accept that they are not available to fight in Isil territory because it is Arab not Kurdish land. So that already knocks the largest and best contingent out of the 70,000.

Why were the Kurds included in the total when the paper itself acknowledges they are not available?

After that, Cameron is really struggling and the paper becomes vague. The paper talks (p.19) of rebel forces who defended the Syrian-Turkish border near Aleppo from ISIL attack.

This is perfectly true, but their leading fighting component is Jabhat-al-Nusra, an open al-Qaida affiliate. They cannot conceivably be described as moderate, and are armed and equipped by Saudi Arabia. Their principle martial activity is looting and raping in Shia villages. There are in fact about two dozen rebel groups around Aleppo – here is a good snapshot – who often fight each other and for the last few months have been losing ground to Assad forces. They are also a primary target of the Russians. It is simply nonsense that they could march on ISIS in Raqqa.

Cameron’s paper then goes on to reference the southern front of the Free Syrian Army, and paints a rather rose-coloured picture of its military prowess. The Free Syrian army can legitimately be painted as less extremist than other groups, with some important reservations, but nobody has ever assessed the strength of its southern branch at over 10,000 fighters. It is completely pre-occupied with fighting Assad and Hezbollah.

After that, the paper is seriously stuck, and goes on to enumerate policemen, “white helmet” humanitarian workers and even local authority engineering workforces as part of the evidence of the existence of moderate forces. Whether any of these groups is included in that amazing 70,000 total is unclear.

What is clear is that the 70,000 figure does not stand up to thirty seconds scrutiny, and there is no coherent plan whatsoever for ground forces to follow up air attack.

The absence of ground forces was an obvious flaw in Cameron’s bombing plan. For him to try to allay concerns by such a huge and blatant lie may prove to be a very poor tactic. Indeed this is so shockingly bad that not only are many Tories privately saying it is difficult to vote for bombing, even some of the still more right wing Blairites are concerned too.