The Cabinet divides into optimists and pessimists about Brexit.  Matt Hancock, for example, is an optimist, judging from his Cabinet intervention this week over higher wages. The leading pessimist is the man he rebuked, Philip Hammond – whose department spews out Eeyorish forecasts of lost growth.

Gavin Williamson seems to be among the optimists.  He has just told me that fellow defence ministers abroad are “absolutely desperate to make sure that Britain continues to be involved in working with them on security and defence”, in answer to a question about whether that part of a Brexit deal is already essentially sorted.

But suddenly he veers off in a new direction.  “Equally, we must not timid about striking out on our own.  I don’t want to criticise you, Paul,  but I have to say that it gets really tiresome when journalists want to constantly focus on the negative. Actually, the great opportunity for us in terms of Brexit is our ability to shift focus – and start looking at new opportunities.”

We are perched in the Defence Secretary’s office in the cavernous Ministry of Defence, with its scuttling, teeming staff, some in uniform, and noses-to-the-grindstone atmosphere.  Suited, tied and sober, Williamson youthful looks strike a contrast with the frowning gallery of all-male predecessors whose photos are ranked around the MOD waiting room in which I was kicking my heels a few moments ago.  Though not uniquely so: perched among the suits, greying hair and spectacles is a snap of a boyish-looking Michael Portillo.

The Defence Secretary is going over the top as part of the traditional weekend pre-Conservative conference Downing Street interview offensive.  His aim is less to take no prisoners than to avoid taking a hit.  Asked if Theresa May can stay on as Prime Minister after a Brexit deal, he says simply: “Yes”.  That one sorted.  He has some verbal ticks.  One is “fascinating”.  Quizzed about whether she will now shift to seek a Canada-type deal, he pauses for a moment, and begins: “it’s really fascinating”.  Probed on the possibility of No Deal, he starts by saying: “this is also something I find fascinating”.  To my disappointment, there is no Cronos scuttling about on his shoulders: the famous tarantula is “having a nice holiday in the constituency”.

On Canada, by the way, Williamson ducks for cover behind the Prime Minister who is an “amazing women with an immense amount of resolve: people often under-estimate her”.  I point out that this doesn’t answer the question, and have another go.  The words “Chequers” and “Canada” don’t pass his lips, but he’s careful not to die in a ditch for the former or to rule out the latter.  “You’ll appreciate that the Prime Minister’s negotiation strategy is for her to play out with the EU.  There are lots of people that love to speculate about the next moves – about how the negotiations are going to – but we’ve got to give her full support in order to deliver the very best deal for us.”

Anyway, back to optimism about Brexit.  The Defence Secretary knows what he’s doing – and understands as well as anyone that negativity about Brexit is to be found as much among his fellow politicians as journalists (and scarcely here at Brexit-backing ConservativeHome).  No, he is making a wider point, and sending up a bit of a signal as he does so.  Which he now goes on to illustrate.  “When I first came into this department, we were talking about how to develop a future combat air strategy – or, in more plain-speaking non-MOD language, another jet fighter to replace Typhoon, and everyone constantly obsessing about how we do this with our European partners”.

“However, sometimes just because this is how we’ve always done something isn’t how it must always be done in the future. So my view is: let’s be liberated by this process. Let’s start to look at opportunities more widely.  For example, what we’ve seen is a rapidly deepening partnership between Britain and Australia on defence – not just on industrial side but on the military side, too.  So there is a danger that we talk down our opportunities instead of appreciating that this constant view that everything must be done in the European context is simply not the case”.

But wouldn’t this British-Australian co-operation be happening anyway, regardless of Brexit?  “It really has started to change,” he says. “I think what you’re seeing is a change in the mindset – starting to lift peoples’ sights higher and in a much more global way. For example, in 2013 we hadn’t had a single naval ship in the pacific region.  This year, you’ve seen what you’ve seen HMS Sutherland there and HMS Albion: HMS Sutherland is absolutely integral to us winning the deal, in terms of a £20 million warship order with the Australians. You’ve seen HMS Argyll going out there – you’ve seen an increasing tempo of activity.”

Pre-conference, Tory MPs are at loggerheads over how to take on Labour.  Williamson’s view is what I would have expected: practical, voter-focused, down to earth.  He is dismissive of the current trend of probing the strengths and weaknesses of capitalism.  “I’ve never been on a doorstep where people want to have a conversation about capitalism…we’ve got to sell to people how schools will be better for their children, how we’re investing in the NHS, how we’re going to continue to grow the economy; that the house that they have they’ll be able to continue to pay for, that the car they want they’ll be able to buy. We’ve got to give them that confidence.”  The struggle with Jeremy Corbyn’s party “isn’t about shades of grey – this is about something more seismic”‘.

Voters are “so much more settled in terms of what they want. They want the government to deliver Brexit. They want the government to deliver the referendum result…if you look at it from the defence context, you will see that so much of what we do is about jobs, investment, and prosperity – in Europe, Africa, the Pacific”.

And at the heart of our defence strategy is NATO, which “will take much more significance to us in terms of being a platform to build co-operation, not just across the North Atlantic, but right across europe – and I think it will now become a much more politically significant organisation, and something that we will invest a lot more time and capital in.

This programme needs more money.  How are the departmental spending review preparations going?  “I’m going to have that opportunity with the Prime Minister and the Chancellor before I have it with you, Paul – I hope you’ll forgive me for that.”  I remind him that those negative stories include a series of apparently well-sourced ones from Whitehall about his disagreements with Hammond. So he won’t mind me asking.  “You’re spot on for doing that, but these conversations will need to be had.”

Gavin Williamson will be in conversation with Isabel Oakeshott about defence at the Conservative Party Conference.  This ConservativeHome event will take place from 8.00 – 9.30 on Monday October 1 in Hall 5 of the conference centre.  “White Flag – an examination of the UK’s defence capability, by Lord Ashcroft and Isabel Oakeshott, will be published shortly.