Quite the scoop in yesterday’s Sun. An anonymous cabinet minister has briefed the paper that to secure Britain’s economic future, we need a baby boom. The birth rate has fallen from 2.93 children per woman in 1964 to 1.58 today. We have an ageing population, and a shrinking workforce, and something must be done.

‘We need to have more children,’ says this minister. ‘The rate keeps falling. Look at Hungary – they cut taxes for mothers who have more children.’ And, indeed, they do. In Viktor Orban’s fiefdom you’re let off income tax for life if you manage to squeeze out four or more kids.

There are other precedents besides Hungary. Much has predictably been made on lefty social media of the fact that Nazi Germany had the same idea – Hitler gave you a gold medal if you produced eight babies or more, which must have been quite the incentive. I can’t say, though, that I quite buy the idea that the policy is tainted by association. We use tax incentives, or similar nudges, to promote all sorts of what we imagine to be social goods. That may be a bit nanny-stateish, especially for a Conservative party that likes to wave the flag for personal freedom and against the dead hand of the state and its zombie fingernail ‘social engineering’. But encouraging a higher birth rate – provided you don’t specify that it’s only Aryans who qualify – doesn’t make you a Nazi.

The question is, rather, what exactly such a policy would hope to achieve on its own terms. As far as I can see it is a crude attempt to tape over a yawning contradiction in Conservative thinking. On the one hand, we are short of labour. I’m told by wiser heads that this can’t all be blamed on Brexit – so much for my prejudices. But be that as it may, we are where we are. We don’t have enough people to pick fruit, serve cappuccinos, wash dishes, build kitchen extensions, look after the lame and the old, and all the rest of it. The government having declared that its three priorities are growth, growth and growth, it has realised that a young and vigorous workforce would be a bit helpful in achieving it.

But the obvious means of doing this would be to allow said young, vigorous workforce to move freely into the country from elsewhere and take up those jobs. That is the free-market solution, the capitalist solution: one that should, on the face of it, appeal to a mindset that celebrates the unfettered movement of resources across the world. At a stroke, productivity would go up, tax revenues from all those wages would trickle reassuringly into the public coffers, and the great wheel of the economy would grind round once more. But that solution is verboten because of we have Taken Back Control, and our borders aren’t supposed to be permeable to immigrants.

Liz Truss – not exactly the queen of bleeding-heart wokery — had the temerity to point out that letting a few more immigrants in might be a help. Even Jacob Rees-Mogg has advanced the idea. But it’s politically tricky. We are blessed with a Home Secretary who is having none of it. Suella Braverman mists up at the thought of deporting people to Rwanda, and wants to see net migration fall below 100,000, and it seems her instincts chime with a core part of their electorate. Being forced to invite more immigrants in to save our bacon would be an unpalatable admission that ending freedom of movement – a central selling point of Brexit – might not have been the greatest idea after all.

The only alternative, then? Grow your own. If we don’t have enough workers to make the economy thrive, we’ll have to breed some more. The main problem with this, as should barely need pointing out, is that growing new workers from scratch has the sort of lead time that makes defence procurement cycles seem like the life of a mayfly. If we all get swiving for victory now, it’ll still take 16 to 18 years before the results will be entering the workforce. Granted, we’d all like to see a bit more long-term thinking from politicians, but this is ridiculous.

The upfront investment involved in getting these children to adulthood is, according to the latest figures, about £200,000. A fair bit comes from the public purse, on top of that – they’ll need educating, vaccinating, tree-climbing injuries fixing up – and the parents will no doubt be hoping to collect a bit of child benefit, not to mention leaving the workforce themselves to look after their ever-proliferating tots. Plus, we’re proposing to reward those parents by letting them pay less income tax when they do return to work. And all in order to ensure that 2022’s labour crisis is solved by, er, 2040.

In practical terms, you could think of babies themselves as a form of immigrant: travellers across our un-policed border with the realm of nonexistence. But these particular immigrants, rather than finding a job on arrival, spend the best part of two decades swinging the lead and sponging off the taxpayer. If just one fully-grown immigrant of the traditional sort were to be caught taking that attitude, they’d be the subject of a shock-horror splash in an outraged tabloid. Yet here is someone senior in government suggesting we actively encourage an uncapped number of them to arrive. Bonkers. Ideology is one hell of a drug.