A magnificent piece of political hokum was announced in the UK yesterday. VAT is going to be charged on hot food. This means that if you go and buy a hot pie or sausage roll you have to pay an additional 20%

No problem on the face of it; until you try to define the term “hot”. Think about it: on a cold day, get in a hot shower and it’s painful. Use the same temperature water on a hot day and you can hardly notice it. It’s all about the ambient temperature, isn’t it? “Hot” is fairly easy to imagine. But, for the sake of an exercise, please consider a warm sausage roll. On a cold and frosty British day it might be just the thing you need to warm you up. On a hot summer’s day it doesn’t do that at all; it feels as though it’s hardly been warmed. It’s the relationship, as any physics student will tell you, between the temperature of the item and the ambient temperature. Heat flows from warmer to cooler. You put something cold next to something hot and, given time, both will become the same temperature, because the hot thing warms the cold thing and the cold thing cools the hot thing.

So what is a hot sausage roll? For sure it has to be above the ambient temperature to even stand a chance of meeting the definition. But how much above? One degree? Ten? Twenty?

One of our leading suppliers of our lunchtime sausage rolls and pies, as well as sandwiches and snacks, is Greggs. It’s valued at over £500 million and employs 20,000 people. It has food shops in most towns in Britain. Yesterday 30% of its share value was wiped off at a stroke at this ludicrous new rule. And it’s not as if Greggs and similar outlets are gaining a single thing from it; all the revenue raised is going in the UK Treasury. I don’t have a problem at all with charging VAT on hot food (ignoring fiscal and philosophical arguments about taxation that are beyond my meagre lukewarm brain) – after all, restaurants and take-away outlets have been obliged do it for years. But if a hot meal equates to black (no, not that steak I burned last week, behave, will ya?) and an ice cream, aptly enough, equates to white, we have all of a sudden dropped into the grey area. What is “Hot”?

Imagine the growing queue in Greggs. “See Janet, children. Janet wants to buy a cold sausage roll. Janet doesn’t have to pay nasty VAT. Lucky Janet. See how Janet smiles. Smile, smile, smile. See John. John wants to buy a hot sausage roll. It looks like Janet’s sausage roll, but this one’s hot. See John’s burned fingers. Ouch, ouch, ouch. John has to pay nasty VAT on his sausage roll. Ouch, ouch, ouch. Poor John. See Janet eat her sausage roll. Yum, yum, yum. See John eat his sausage roll. What’s that, John? It’s not hot? Better join that queue and take it back, John; get back your nasty VAT. See the shopkeeper saying “It was hot when we sold it. No refund. See John ram cool sausage roll where the sun don’t shine. Ouch, ouch, ouch.”

Methinks those queues are going to get longer. Tempers will rise as temperatures fall.

And who will enforce it? Will there be specially trained tax inspectors going round every town every day pushing probes into people’s lunches and calculating the excess temperature above ambient? Will they sterilise the probes between stabs and have separate probes for vegetarians, lactose intolerants, gluten intolerants, people allergic to nuts, religious minorities…? There are some serious health and safety issues here, not to mention all the political correctness issues.

But I guess we’ll have to grin and bear it. There’ll be an on-cost of course. Someone will have to pay for all those inspectors with all that equipment. But who will foot the bill?

I know… they could raise VAT on hot pies…