Early on the morning of Friday 24 June, Darren Gratton went into his butcher’s shop in Barnstaple and changed his wall signs, which at this time of year are mostly about barbecue packs. Emboldened in the Brexit dawn, he deleted all references to ‘kg’ and replaced each one with ‘lb’. Tempted to do the same to the labels inside the display cabinets, he decided not to, for fear of a threatening call from Trading Standards. But that small act of wall-chart insurrection was enough to spark an article in the local paper, which triggered a deluge of emails from other shopkeepers across the country in support of his brave action with the squeaky pen.

As Britain turns its face towards the exit door, and butchers dare to erase their kilo-gram signs, some are asking: will justice now be done for the Metric Martyrs? One of the many who emailed Gratton in support was Neil Herron, the steadfast campaigner for the five Metric Martyrs, whose criminal records still stand. I met Herron in London this week, and he told me that the Brexit vote has given his campaign a nudge towards his passionately desired outcome: a posthumous royal pardon for his old friend the Metric Martyr Steve Thoburn.

Remember the Metric Martyrs? The fishmonger and greengrocer in Camelford, the market trader in Hackney, the greengrocer in Sunderland, all convicted in the early 2000s for using imperial scales and labelling? It was one of the darkest times for the EU’s reputation in Britain. If we’re looking for specific reasons why so many people voted Leave, it’s worth contemplating the lingering ill-feeling left by those small acts of bureaucratic bullying, when the ‘little guy’ going about his daily business was squashed and criminalised by the rigid mechanics of Council Directive 80/181/EEC, stipulating the use of metric measurements, incorporated into English law in January 2000.

Just a month after that statutory instrument was nodded through Parliament, attaching criminal sanctions to the directive, police officers marched into the Steve Thoburn’s shop in Sunderland, seized his three sets of imperial scales and charged him with ‘using scales not certified for trade’ to sell bananas. On that day, Herron sat Steve down on a sack of King Edward potatoes and said, ‘Steve, you’re going to be the most famous greengrocer in the world.’

And he was. He and Herron took the case through the courts all the way to the European Court of Human Rights, where their appeal was rejected. The court of public opinion was overwhelmingly on their side, but the law wasn’t. It was a small but unforgettable example of the surrender of sovereignty. Thoburn died suddenly of a heart attack, aged 39, with a criminal record. Herron will now not rest until his old friend is granted a Turing-style royal pardon, and he believes that ‘the timing and the mood’ are right for this to happen.

The situation, if you go into butchers’ and greengrocers’ shops across the country, is a fudge. A typical British anomaly and mess, in fact. When we walk into a shop and ask for a pound of apples, we’re inciting the seller to commit a criminal offence. The actual arresting, charging and convicting has stopped for the moment, thanks to the minister John Denham in 2008 saying ‘Enough is enough’ after Janet Devers, a market trader in Hackney, was threatened with not being allowed to visit her relatives in the USA because of her criminal record for selling fruit by the pound, and the New York Times published this piece of absurdity. Now more of a blind eye is turned. But it’s a grey area and a stalemate; and the time has come, Herron and his campaigners say, to ‘strike down the repugnant piece of EU legislation’ that makes selling by imperial measures a criminal offence.

I’ve talked to butchers in Helmsley, Hull, Barrow-in-Furness, Whitby, Diss and Lowestoft over the last few days — a joyous thing to do, as they’re still family firms of many generations’ standing, and if they’re called ‘Willison’s’, you actually speak to Mr Willison — and they all tell me the same thing: 95 per cent of their customers ask for their meat in pounds and ounces. Not only the older customers: young ones, too. The butchers know the conversions by heart: 1lb of sausages is 455g. Some have scales that can go from imperial to metric with a flick of a switch. That switch is swiftly flicked whenever the Trading Standards people come in. Only Mr Laing in Barrow-in-Furness said, ‘We just use imperial, really. We’ve never gone over to metric.’

Market traders, as anyone who goes to street markets will have noticed, have gone over mostly to selling fruit and vegetables by the £1 plastic bowl, as a way of avoiding the whole weights-and-measures issue. This is, strictly speaking, also against the law — but everyone does it. It’s rather sad, as the rows of plastic bowls look much less enticing than great heaps of apples and oranges, and they make the experience of going to a market as dreary as going to Poundland. Bowls eliminate the need for conversation: customers simply point to a £1 bowl and the seller tips it into a bag, and not a word is exchanged. It makes for rather quiet mornings in Hackney.

The truth illustrated by Britain’s stubborn refusal to change its ways and think in metric measurements is this: you can legislate for how things must be described, and for how people must speak, but it’s almost impossible to legislate for how people think. The fact remains that millions of us British still think in pounds and ounces — a fact gloriously shown to be the case when Tony Blair’s baby Leo was born in May 2000 (three months after Thoburn was criminally charged) and the baby’s weight was announced by Downing Street as ‘6lb 12oz’. Of course it was. If they’d said 3.06kg, no one would have had the faintest idea whether Leo was a bonny baby or a puny one. The story of the bananas, the pounds and the criminal records is a trivial but illuminating example of why the EU failed in Britain. In the interest of so-called fairness, dull uniformity was imposed, and we wouldn’t have it.