The government has published the assumptions that underpin its no-deal preparations. I've gone through the document at length here, but the headline assumptions are that there will be increases in the cost of fuel and food, possible shortages of medicine and potentially riots as a result of all of the above.

The government's rhetorical shield is that this is just the reasonable worst case scenario – which is a clever way of hiding that it is also their central forecast. Yes, it's possible that it could be better – but it is equally possible it could be worse.

It reinforces one of the major no-deal preparation problems – something flagged in this report, too – which is that business and household readiness for a no-deal Brexit is going to be inadequate and patchy. How could it be otherwise when the government's public posture on no deal oscillates wildly between “Get Ready!” and “Don't Worry”?

And that's the central divide at the heart of the government – is no deal a political posture to knacker the Brexit Party and secure a “better deal”, whatever that may be? Or is it the government's preferred and most likely end state? Johnson's appointments both in cabinet and in Downing Street face both ways, and the government's no-deal preparations reflect that confusion. The British government has shown an appetite for briefing about its seriousness about no deal – and a reticence to do anything – like building the necessary infrastructure around ports – that might be unpopular with Leave voters.

And the troubling thing, for both Johnson and the country, is that the unity position between those two schools of thought may well be to go for no deal, but in as poorly planned and managed a way as possible.