Diplomats, and European ones in particular, take matters of status, protocol and etiquette very seriously, and the snub looks, on the surface at least, designed to diminish our closest neighbour. The ambassador for, say, Mozambique, or Honduras, has full diplomatic recognition, but not the person representing the 440 million strong trading bloc on the other side of the English channel. Wars have been started over lesser slights.

But hold on. Sure, you can argue that the UK is being silly. But so is the EU. Lorries are being searched for illegal British sandwiches. Fish are being checked for any kind of disease. Musicians could have to apply for dozens of visas. There is nothing wrong with playing tit-for-tat. If the EU is being difficult, we should be difficult back.

It is certainly possible to have an argument about the status of the EU’s mission in London. From our point of view, the EU is not a country – let’s not forget we have had years of lectures from some Remainers about how it had no ambitions towards statehood – and so its officials can’t be diplomats. If any kind of supra-national organisation was allowed to claim that, its value would quickly be diminished. Against that, most countries around the world offer diplomatic status to the EU’s officials. Even Donald Trump’s America, after initially refusing to, came round to doing so.

Most importantly, there is no question it will irritate Brussels. Michel Barnier, now in charge of implementing the agreement he spent years negotiating, and always a man quick to take offence, has already expressed his displeasure. The important point, however, is surely this: the EU is being petty as well.

The snarl-ups we have seen so far since our transitional arrangement came to an end at the close of last year (and there have clearly been a few) mainly result from zealous policing of the paperwork by French and Dutch officials. Indeed, for the EU to start complaining about the petty enforcement of minor rules is more than a little rich. That is one of its main specialities. It is hard to see how it can moan when the British start enforcing the rules as well.

In truth, there is no harm in the UK playing tit-for-tat for a while. Every time it is difficult about something, we can be difficult back. As we learned from the trade agreement, if you stand up robustly to Brussels then the EU quickly compromises. Sooner or later, relations between the UK and the EU will settle down into a slightly irritable coexistence. In the meantime, there is no harm in pettily enforcing the rules – even if it does put a few diplomatic noses out of joint.