Nowadays you don’t need to launder your money.

Three years ago the Bank of England gave us shiny new polymer £5 notes. Polymer tenners followed in 2017 and polymer £20 notes will come next year. Nice, clean £50s are promised after that – not that I’ll see one very often.

So why, when filthy lucre is becoming less filthy, are we being encouraged to ditch it?

I was first surprised by the growth of contactless payment on a trip to Croydon, when I tried to pay cash for a bus ticket. My pockets were laden with coins so I could helpfully hand over the exact money. But Croydon bus drivers only accept plastic.

It’s set to get more common. In 2005 cash and notes made up 64 per cent of all payments in the UK, and by 2015 this had fallen to 45 per cent. By 2025 it’s expected to have dropped to 25 per cent.

Digital payment is supposed to be more secure, of course. You can’t hold up bus drivers and demand they hand over their cash if they’ve got no cash.

It’s safer for individuals too. We can cancel our bank card if it’s stolen. We can’t cancel a stolen £20 note.

We’re all familiar with the closure of bank branches and the removal of hole-in-the-wall cash machines. But this assumption that everyone is happy with electronic payment now is all wrong.

Studies show that 17 per cent of the population would find a “cashless society” difficult to deal with. That’s more than eight million adults.

It would affect the elderly and more vulnerable people most of all. The trouble with the speeding digital bandwagon is that some of us can’t climb aboard.

And I’m sure there’s a hidden agenda behind it. It’s not just about safety and security. It’s about encouraging us to part with more of our money.

We do that a lot more readily when we don’t use cash. When money isn’t something physical, sitting in our pocket, purse or wallet, we’re disconnected from it., it’s far easier to spend it.

It matters more than ever now as household debt reaches record levels as the cost of living rises while wages for many of us stay the same. Going cashless does nothing to help us cope.

There’s a creepier side to it too. Hand over cash for goods and that’s the end of it. Pay any other way and you’re under surveillance.

Anyone who’s ever bought anything via Amazon will know how they get bombarded by emails for months afterwards, as the company use the information they’ve gleaned to make assumptions about what else we’ll buy.

Card spending allows companies to gather all sorts of details about our lives, from where we travel to the books we read, the TV we watch and the food we eat. Big Brother is watching you, just as George Orwell warned 70 years ago.

It could be that the whole world will soon go cashless and these new polymer notes will be rendered obsolete – just as email pretty much did for faxes.

But let’s at least offer people the choice. We’re supposed to be a compassionate and liberal society, which excludes no-one. Public buildings have to make reasonable adjustments to accommodate wheelchair users, blind people and deaf people – and rightly so.

Let’s make room for people who don’t trust cards, those who want to guard their privacy against big corporations and anyone who just prefers to deal in cold, hard cash.

In any case foretelling the death of money as we know it is probably premature. When cheques were invented there were probably predictions that they would spell the end of cash. Maybe when banknotes were first printed the expectation was that coins would disappear.

And it’s always worth keeping old coins and notes before they vanish. They become collectors’ items and you’ll find their increase in value always exceeds inflation.

Last week Cockermouth auction house Mitchells held one of its regular three-day antiques and fine art sales. Among the 2,000 lots was a 554-year-old coin.

It was an Edward IV groat, minted in 1465 and originally worth four pence. It sold for £240 – twice as much as expected and 6,000 times more than when it was made.

When old, paper tenners went out of circulation I was careful to set one aside, and lost it. I’m hoping it turns up when I go looking for the old-fashioned fiver that I also lost.

It could be worth a lot in 554 years’ time. My descendants will thank me.