A couple of months ago, I warned that the enthusiasm of some Conservative politicians (Sarah Wollaston, I’m looking at you) for dour, miseryguts policies – taxing puddings and sweets, bringing the weight of the state to bear as a tool to bully people for having a little joy in their lives – could be bad for the Party’s political health.

Those ideas were bad enough, but full marks to the Treasury for managing to further and produce a vastly worse idea: taxing vaping.

The established tendency to see any innovation as an opportunity to invent new taxes is well-known. The Treasury sometimes seems to have taken the old Ronald Reagan critique of statist economics as an instruction manual: “If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidise it.”

That’s not a healthy attitude in general. It would be particularly harmful – and hypocritical – in the case of a vaping tax.

The history of ‘sin taxes’, like that on tobacco, is a counter-intuitive one. Over time the state has come to rely on the continuation of the sizeable revenue it gets from a tax that was meant to eliminate itself by deterring people from smoking. That situation became, in effect, a conflict of interest between the stated public health objectives and the practical fact of multi-billion revenue.

In the meantime, the old idea that the free market would never be able to challenge addiction to smoking has turned out to be something of a myth. The invention and popularisation of vaping has done exactly that – providing a route out of smoking for millions, and for many of those ultimately off even nicotine altogether – all with what Public Health England say is a technology that carries something like five per cent of the harm of tobacco.

In short, vaping has saved lives, is saving lives right now, and has the potential to save many more.

The effect on the anti-tobacco lobby has been revealing: many have stuck to their principles and recognised that vaping does what they said they wanted, while a rump have revealed themselves to simply be opportunistic puritans, philosophically and ideologically opposed to the concept of nicotine consumption regardless of the scientific and medical facts that they previously claimed as their justification.

Thus far, the taxers and regulators Reagan joked about have mostly kept their hands off this success story. The EU’s Tobacco Products Directive intervened messily in the market on things like bottle sizes, adding unnecessary costs but mercifully without killing off vaping itself.

If the Treasury were to a step further and apply a tax, what do they think they would be achieving? It wouldn’t be a “sin tax”; quite the opposite, it would be a tax penalising people for stopping smoking, and with the probable effect of deterring some from doing so. People would die, and public health – that cause on which the very same Treasury spends quite a lot of money – would suffer accordingly.

If miseryguts taxes on life’s little joys are spiteful, a tax like this would be out-and-out harmful. It should be knocked on the head.