Even if they do, no one who is enrolled in this scheme should rely upon it for an old age of undiminished prosperity. The numbers cannot be made to add up. When Bismarck first gave Prussians a state pension, their average expectation of life was 46, so he could set the retirement age at 65 and run a solvent scheme — but since then lives and retirements have lengthened and the cost of providing for them has rocketed. While we wait, some government is sure to change the rules, not necessarily in our favour. The history of our state pension and the second income tax tells that unhappy story.

Now we have a new scheme that will work like a tax. Employers must suffer their share and must also carry the costs of collection. Their employees will feel it as a hole in their pay packets. They will be told that their bread is being cast on the waters and will return to them, as the Scripture promises, after many days. That may not enthuse them if they have bills to pay at the end of the week.

It may not enthuse the Chancellor, either. He is counting on them to keep the recovery going and he does not want to prune their spending power. Observe his sudden conversion to the joys of higher wages — if need be, compulsory. It would not serve his purpose to hit those wages with a higher tax from which he does not even benefit. On the contrary: the tax relief on their contributions will make his arithmetic worse.

He is now audibly casting doubt on the whole structure of this tax relief. It is meant to encourage us to take out pensions, or to have them taken out for us — but when we collect them, we pay tax on them. May we be doing this the wrong way round? Imagine, instead, that we paid tax first and saved later, but that from then on our savings were tax-free.

This model, in fact, has been working well for decades, under different governments. It is known as the Individual Savings Account, or, less formally, ISA. We get no tax breaks for contributing to an ISA, and pay no tax bills of any sort on the money in the account. Pension contributions are, of course, a form of saving. Why not say so?

If the Chancellor is minded to say so, he will need to hurry, for the third income tax is tightening its grip. He could begin by explaining that the scheme will be genuinely optional. For a start, anyone who is offered a better deal should be free to take it, without the police turning up to arrest his employer. Then tax reform would follow. 

Two principles should be at work here. First, we should never trust the government — any government — to look after us in our old age. Next, as the Commons so sensibly recognised, one income tax is more than enough.