When you drive across Norfolk, the first thing that strikes you is just how much of the county is given over to the production of food. We have always been an agricultural county, and we are still responsible for producing around a tenth of the nation’s food output.

So you could be forgiven for wondering why, when the fields around us are seemingly groaning with edible produce, that there are so many gaps on our supermarket shelves.

We are not yet at the stage of Soviet-era style queues for staples such as a loaf of bread, but at the very least our choice is becoming very limited, even of things like fruit and vegetables.

When the pandemic first hit, and we were fully locked down for the first time, many people had serious worries about whether our food production, logistics and distribution systems would be able to keep the nation fed.

Against all odds, at no stage was the flow of food interrupted, and we owe all of those working in the sector a huge vote of thanks for going above and beyond to ensure we didn’t go hungry.

Fast forward 18 months, and we are supposedly finally emerging from the Covid crisis, thanks to some pretty draconian (but necessary) restrictions on our freedoms, and the success of the vaccination rollout (the one part of all of this which was kept in-house in the NHS and not offered on lucrative privatised contracts to chums of cabinet ministers).

So why are we only now coming across empty shelves, restricted choice in the supermarket, and even the prospect of rationing of some items?

The answer lies in three different factors: the first, of course, is that Covid is actually far from over, and the so-called ‘pingdemic’ is having a dramatic effect on the UK’s ability to keep the supplies rolling.

Secondly, this is being exacerbated by Brexit, of which we are only now starting to feel the full effects.

Many hundreds of thousands of food production workers, lorry drivers and other key workers from EU countries have gone home, both because of Covid and because of an unpleasant feeling that they are not welcome here anymore.

The third reason is rather more structural: the fact is that Britain has been unable to feed itself since the early 19th century, and has relied on trading relationships and co-operation with other countries to do so for 200 years. Having taken the decision to go it alone, we shouldn’t be surprised that those mutually beneficial relationships are not delivering in the way they used to.

The former Downing Street adviser Nick Timothy (a kind of low-rent Dominic Cummings) sent out a supposedly witty tweet last December in which he said ‘Younger voters might not know this but Britain simply didn’t have food before 1973. Past generations used to live off a diet of pebbles and muddy rainwater’.

In attempting to debunk legitimate fears about the effect of Brexit on our food security, Timothy actually reveals his own ignorance.

In point of fact, in the early 1970s Britain was indeed facing a food supply crisis, as producers abandoned Commonwealth trade agreements in search of more lucrative markets. Supermarkets actually introduced rationing, and shoppers were restricted to one loaf of bread each, leading to Soviet-style queues outside bakeries.

It was largely this situation which led to the British public ratifying membership of what was then the EEC in the 1975 referendum. Warnings about interruptions to our food supply couldn’t be dismissed as ‘Project Fear’, because they were already happening – as they are starting to again in 2021.

The food production sector has changed dramatically since then. It is much more efficient, logistics are far more sophisticated, and the price of food has fallen. What hasn’t changed is that we are still very far from being self-sufficient in food, and the fact that trading partnerships with other countries are vital if we are to be able to feed ourselves.

Concluding small-scale trade agreements with countries like Australia – especially agreements that are so one-sided that food producers down under can’t believe their luck – will not fill the gap left by our decision to cut ourselves off from our nearest and biggest food trading partner bloc.

Nor will wishful thinking about upscaling the UK agricultural sector come anywhere close to bringing production at home anywhere close to the level needed to avoid those empty shelves.

It’s perfectly legitimate to argue that the EU model is wrong, and that we should be searching for a new one. But as crops rot in the fields, produce remains stockpiled in warehouses because there are no lorry drivers to move it around, and empty shelves stretch the length of aisles in supermarkets across the land, we have yet to hear the Brexiteers’ grand plan to provide a viable alternative.