The fact that supporters of Liam Fox, like Tim Montgomerie, are openly talking about his likely successors, demonstrates just how deep in the doo-doo the Defence Secretary is in. In some ways this is one of those political squalls all politicians go through at some point in their careers, but this one feels, well, as if it has legs. And if the Westminster lobby senses that Fox has been wounded, they will go in for the kill.

The trouble is that Liam Fox has quite a few enemies. And not all of them are in Number 10. The others are predominantly in the senior echelons of the military. They can’t stand him, and you can bet your bottom dollar that they have been briefing the Sunday papers like there’s no tomorrow.

So what’s the case for the defence? Well it’s certainly not the one just advanced by Tim Montgomerie on the TV just now. He reckons that Fox will be safe as, apart from IDS, he’s Cameron’s only Cabinet conduit to the right*. That simply won’t wash. If you’re going to defend Liam, you have to do it on the facts of the case. These are the questions which Fox needs to answer, according to Patrick Hennessy…

  • Why did Mr Werritty, 34, visit the Ministry of Defence 14 times in just over a year, despite not being a government employee, and join Dr Fox on an official ministerial trip to Sri Lanka this summer.

  • Has Mr Werritty ever had access to any classified MoD information?* How was Mr Werritty able to broker a meeting at a Dubai hotel in June between the minister and businessmen to discuss technology that allows service personnel to make encrypted phone calls home and according to them, a commercial dispute with American firm 3M?

  • Why, until he was told to stop doing so, Mr Werritty also handed out business cards bearing parliament’s portcullis logo which described him as “advisor [sic] to Rt Hon Dr Liam Fox.”

  • Is there any truth in claims that Dr Fox had agreed to raise the Dubai-based company’s dispute with 3M in Cabinet?

These are a lot of questions. There can be little doubt that Fox and Werrity are close friends. The question here is about judgement. Werrity’s judgement is clearly in question - you just need to look at the business cards to know that. But is Liam Fox’s? Anyone who knows Liam knows he’s basically a nice guy who is keen to impress and keen to please. He is a friendly guy. He doesn’t like saying no. So is it possible his best friend asked him to do something and he said yes? Entirely. Would he have necessarily thought through the consequences? I doubt it.

I was just discussing this with an MP of my acquaintance. I said that if DD had been Defence Secretary it is entirely possible I might have visited him in the MoD 14 times in 16 months. I certainly wouldn’t have had a business card saying I was his advisor, but if politicians aren’t even allowed to see their best friends in their departments, we are entering a very dangerous world. The difference between me and Mr Werrity is that none of my business interests are in the area of lobbying or defence. And that’s where Liam’s danger radar should have been twitching. Or maybe one of his special advisors should have alerted him to the danger.

The Guardian’s emails from Harry Boulter about the meeting with Fox and Werrity look bad. They will look even worse if it turns out there was any financial relationship between Werrity and Boulter. Unbelievably, the Guardian doesn’t seem to have asked him the question!

The other reason we know that Liam is in trouble is because Number 10 made public that the PM had asked the Cabinet Secretary for a report by Monday morning. That didn’t need to be made public, but it was. Draw your own conclusions. Why the haste? Because there are Defence Questions on Monday. Jim Murphy will also ask an Urgent Question, which I suspect The Speaker will grant. It’s also possible there could be an UQ to the PM as this concerns a possible breach of the Ministerial Code. It’s possible but not probable that Bercow would grant that. Basically, Number 10 is trying to insulate itself.

It’s clear there is little love lost between Cameron and Fox. The PM is said to be convinced that Fox leaked the letter on defence cuts he wrote to the PM a few months ago. Cameron would shed no tears over his departure from government, especially as in these circumstances he would be a busted flush politically. But - and it’s a big but - the reason Number 10 may in the end want to put a plug in the plughole before Fox disappears down it is because there is no readymade replacement. Stick with nurse for fear of worse, may be the mantra among some of the less daring advisers in Number 10.

Tim Montgomerie tweeted earlier that Owen Paterson would be an ideal replacement, as he would appeal to the right. Guess again. Harry Cole is touting David Davis. I’ll plead the 5th on that one. The name being mentioned by many is the International Development Secretary, Andrew Mitchell. We’ll see. Or perhaps not.

I think Liam Fox can survive. But only if he comes out fighting and quickly. He’s got some powerful enemies ranged against him. If he hasn’t seen them off by Monday lunchtime, he may live to regret it. It may be too late.