This is grim enough. It suggests that the flow of freight through the ports could be reduced by between 20% and 40%, while trucks travelling in either direction could be delayed by up to two days: a big problem for fresh food. This month, the National Audit Office reviewed the government’s border arrangements, and found them to be late, untested, “inherently complex”, “high-risk” and “very challenging”. The government’s brinkmanship, intended to wrongfoot the EU, has instead wrongfooted our own hauliers and traders, who have been unable to prepare with confidence.

So far, so bad. But the UK’s border is only one link in the food supply chain, and it may not be the weakest. If the ports are congested and the flow of goods reduced, we will need stocks to bridge the gap. Food traders will have to build reserves, now and in December, to cover the likely shortfall in January. This means warehouse capacity. One minor hitch: there isn’t any.

Because of the shift to online sales caused by the pandemic, and the need to store protective equipment, much of the spare capacity was mopped up before the second lockdown. Now, because nonessential shops are closed, plenty of stock is stuck in warehouses. Any remaining space has been swallowed by Christmas: tinsel, toys and turkeys. Goods for the domestic market will have to compete for warehouse space with goods for export, as traders expect snarl-ups in both directions.

A survey by the UK Warehousing Association found that there is less than 3%spare capacity nationwide. Most of this consists of small corners, useless for major wholesalers. The association believes “the situation will quickly become critical”.

While the government has spent £1.4bn this year on border arrangements that would usually be made by the private sector, it has done nothing to ensure there is sufficient storage space, or that food is prioritised. Such issues, it believes, are best left to business.

But its confidence in the food industry is not shared by the industry itself. In October, the chair of Tesco warned of fresh food shortages for “a few weeks, possibly a few months” after 1 January. The UK imports 62% of its fresh food, much of it from Europe. We rely on European trade for most of our onions, mushrooms, tomatoes and salad, and for a critical portion of many other vegetables and fruits. In the dead of winter, with trucks stuck at the border, possible tariffs, a weaker pound and no warehouse space, the price of fresh produce could go through the roof. If you can find it at all.

Last year, before the transition deadline was extended, the government did conduct wider risk assessments. When they were leaked, we discovered that it foresaw “potential consumer panic and food shortages”. This year, though the situation is greatly complicated by the pandemic, it seems to have decided that it’s best not to ask.

Is the problem confined to fresh food? With neither strategic food reserves nor a strategic risk assessment of warehouse capacity, I’m beginning to wonder. Without testing every link in the chain, the government has no grounds for dismissing the threat of an overall shortage. While it now seems almost certain that we will face a dearth of fresh fruit and vegetables, could there also be deficits of some kinds of frozen, tinned and dried food?

Already, thanks to a combination of austerity and the coronavirus, plenty of people in the UK struggle to afford a good diet. According to the UN, a healthy diet costs five times as much as one that is merely adequate in terms of calories. The number of people using foodbanks this year has risen by nearly a half. Any interruption of supply will hit those in poverty first, and worst.

When the government was challenged on this issue in parliament last year, it claimed it was “not responsible for the supply of food and drink to the population in an emergency”. That is up to “the industry”. In other words, little has changed since the Irish famine of the 1840s and the Indian famines of the 1870s. It’s the same reckless, uncaring attitude that has helped kill 50,000 people in the pandemic.

Because we are leaving the single market and the customs union, the disruption is likely to be brutal, whether or not a deal is struck. If Brexitcauses further economic rupture, the shops are half-empty and even the foodbanks can’t find enough supplies, there is a real prospect of chronic hunger. But search as you may, you will find no one in government who gives a damn.