For the first time in over 50 years, food and drink imports from this week will be scrutinised and certified at the UK border. But incredibly, there are still big questions to be answered over how the new Border Target Operating Model will work, or indeed whether it will work, with claims that the queues will stretch all the way back to Paris when the virtual trials now taking place are replaced with the live system in late April.

The latest bombshell to emerge is the upgrade of certain fruit & veg – including apples, carrots, avocados and sweet potatoes – from low risk to medium risk. A temporary easement is in place for now, but the Fresh Produce Consortium estimates it will cost an extra £200m.

There’s also a requirement for 24 hours pre-notification on medium and high-risk goods. Including the 700,000 tonnes or so of bacon we import from the EU. Who will bring it home?

Meanwhile, export health certificates to EU member states have only just been translated. And there are omissions, including liquid egg, of which we import over 40 million kg for use in desserts, mayonnaise, sauces and baked goods.

The real crunch point will be April, when the SPS (sanitary and phytosanitary) inspections kick in, but we don’t know how many and how often they will be carried out. That’s compounded by the chronic lack of vets in the EU. At least that’s one thing we can’t blame on British mandarins.

And worryingly the Sevington inspection facility is not only 20 miles away – a biosecurity hazard in its own right – but doesn’t have the facilities or trained staff to carry out some of the required inspections.

Then there’s groupage. No one knows what counts as a consignment, potentially dragging in low-risk items. And even if and when detailed guidelines are forthcoming, the lack of resources and trained staff at Sevington means officers are still unlikely to pick and choose.

We don’t even know how the common user charge is going to work. There’s a ‘flat’ fee of £20-£43 to pay for the new border controls, but there’s still no guidance.