Isabel Oakeshott is currently writing a book on the state of the armed forces with Lord Ashcroft.

Cross-country running in the Cotswolds last weekend, I was excited to spot a fine March hare. Sadly it scarpered before I got close – with all the speed of the hare that Michael Gove has set running.

Liberated from ministerial responsibility and relishing his return to journalism, the former Education Secretary recently took up position at his desk, stroked his chin and pondered what he might cobble together for his new column in the Times the following day. The result was a half-heartedly argued piece of polemic about slapping VAT on school fees, on the spurious ground that independent schools are like any other luxury service or good.

To some, Gove is now merely a sheepish backbencher, whose opinions stopped mattering after his humiliating exit from the Conservative frontbench. But the truth is that he is far more important than that.  Like it or not, the combination of his personal profile and his political, media and intellectual connections makes him too influential to set hares running in this glib fashion. This particular furry animal has a variant of myxomotosis.

Like the bunnies deliberately infected with that disease to control the rabbit population in the 1950s, Gove’s animal is spreading its own virus, and it has already found a ready host in the Labour party. Now Angela Rayner, Labour’s energetic Shadow Education Secretary, has announced VAT on independent school fees as party policy.

Alarmingly, the usual consolations that apply to Cobynista lunacies – that the architects will never be in a position to implement their misguided ideas – offer little reassurance in this case. Gove’s big new idea is beginning to infect elements of the Conservative Party. Indeed, it is proving so virulent that even writing about it may encourage the contagion to spread. Under Labour’s new policy, the cash raised from school fees would be used to pay for universal free school meals.  I can just see the current party leadership salivating over the mental image of trustafarians paying for turkey twizzlers.

And that is exactly what will happen if they press ahead with the plan. Private schools won’t go out of business: they will simply move further beyond the reach of aspirational middle-class parents who judge that the free educational provision on their doorstep is not the best they can access.

School fees are already rocketing at three times the rate of wage inflation, with some boarding schools now charging more than £40,000-a-year. In London, fees have risen by 25 per cent in the last five years alone. These days, only those with exceptionally high incomes, those with inherited wealth and Russian oligarchs can afford this kind of cash. Even Gove would struggle to argue that buying education is tantamount to splashing out on a flat screen TV or velvet sofa. What is being purchased by those who can scrape together the cash is nothing less than life chances.

This issue has particular resonance for me, being the grateful product of a private education paid for by parents on the relatively modest income of one middle-ranking civil servant (and, when I reached sixth form, subsidised by an extremely generous academic scholarship.) I could paint a vivid picture of the sacrifices they made to send me and my siblings to posh schools: no central heating; no fancy foreign holidays; no new clothes – yada yada. You know the script. Even with further sacrifices, on the same level of income today, my parents would have had no hope of giving what my father believed was the greatest gift you can bestow on your children: the best education you can possibly provide.

Gove’s rationale is what he labels the “burning injustice” of “tax advantages” enjoyed by private schools. He’s referring to that old chestnut – their charitable status – which, as Education Secretary, he rightly made it his business to force the beneficiaries to do far more to justify.  While it is no surprise that the current Labour leadership has leapt at his new idea, neither the moral nor the economic arguments stack up.

For a start, private schools now have a duty to share their facilities and teachers with local communities to meet the “public benefit test” set by charity law. Most are more than willing and proud to do so, and go far beyond what is required by law.

Moreover (according to financial modellers at Oxford Economics), the tax relief for most independent schools – around £150 million a year – is dwarfed by the £3.6 billion a year they generate in other tax revenue (they remain eligible for some business taxes). Then there’s the huge saving represented by the 580,000 children in the private school sector at any one time who do not have to be educated by the state.

Gove further argues that parents who through hard work or good fortune are in a position to exercise educational choice do everyone else a great disservice by opting out of the state system. He believes a “critical mass of academically ambitious students and parents” should “act as a spur to higher standards for every child.”

It’s a fancy way of saying that affluent parents and their kids can have an improving effect on everyone else, and that, at some vague point in the future, this altruistic exercise will make everything equal, reducing the market for private education to a handful of determined snobs. I look forward to this utopia – but what matters to parents is what’s available right now. While the UK languishes beneath Vietnam, Poland and Estonia in the OECD’s international education league tables, there can be no justification for making a political example out of parents who choose to opt out.

Under Tony Blair, New Labour recognised that that stamping on aspiration is never a vote winner. That may not concern Corbyn and his circle who show little interest in what happens at the ballot box.  Tories care rather more about the verdict of their own natural supporters. Gove’s March hare should be swiftly euthanised.