Few things get the British quite as worked up as private schools. To the left, they are factories of inequality that turn scions of privilege into the elite of tomorrow. To the right, they are an expression of parental choice and part of Britain’s schooling heritage. To ambitious mothers and fathers, they are a way to boost the professional and social chances of their offspring. To many others, they are the source of every smarmy, over-confident midwit ever encountered in life.

Their fees are also exempt from VAT, which is a sore point for a lot of people. Not because it means the exchequer loses out on a great deal of money but because it feels wrong in principle. Why should people who can afford to spend tens of thousands of pounds a year sending their sprogs to snooty day or boarding schools get a tax break to help them pay for it? Better to spend that money improving state schools.

That is essentially Labour’s position and the party is pledging 20 per cent VAT on school fees if it wins the next election. Politically, this is a win-win policy for Labour. It panders to the prejudices of the party’s traditional voter base while carrying very minimal electoral risk, since only a tiny slice of the population enrols its children in private schools and they are not a natural Tory demographic.

Already, there is considerable pushback against Labour’s plans. The Adam Smith Institute has produced a paper making the kind of arguments you might expect them to make, including the likely impact on state schools of a sizeable migration of pupils out of the private and into the state sector. The ASI’s best case scenario forecasts 5 per cent migration and the generation of £1.02 billion in revenue, while a gloomier eventuality would be 25 per cent migration and additional costs for the Treasury of £1.58 billion.

While the ASI approaches these questions from a very ideological perspective, its objections should not be dismissed out of hand by supporters of Labour’s policy or opponents of private education more generally. The ability of local authority schools to absorb pupils leaving a suddenly less affordable independent sector is an important question and a real unknown. There is a matter of principle at stake, too. Do we believe it is morally right or socially beneficial to tax education? And, if we do, why should we limit it to private primary and secondary schools when higher education would raise much more in revenue?

These qualms must be balanced against the perception that independent schools contribute to inequality and unfair advantage. One manifestation of this is the seeming correlation between independent schooling and recruitment to the top jobs in Britain. Only 7 per cent of British children are educated outside the state sector, yet the privately educated are wildly over-represented in the ranks of politics, government, law, media and finance. Of the 32 ministers who are members or attendees of cabinet, 63 per cent were privately educated. MPs went to fee-paying schools at a rate four times that of the electors who vote for them while the figure for peers is double that.

The solution is to cap the recruitment of private school alumni in sectors where they are currently over-represented

Six in ten permanent secretaries were schooled privately while one in four Treasury officials of any level attended an independent school. Diplomats are seven times more likely to have swerved the state sector than the public at large, while senior judges are nine times, public body chairs six times, and police chiefs and local government leaders three times. UK-educated FTSE 350 chief executives are seven times more likely to have been sent to private school and BBC executives four times.

There are other, non-equality based arguments against this educational distortion of elite professions. Given the narrow and unrepresentative nature of private schools, it may not be desirable to have key national decisions made and implemented by a demographic with such limited experience of the lives of more than 90 per cent of the country. If we are concerned about the disconnect between elites and the country they rule over, it is reasonable to ask whether a cloistered, privileged education makes things worse.

Whether we decide that private schools are part of the reason for this disconnect, or we object to them on standard egalitarian grounds, we need not embrace Labour’s policy as a remedy. There is another way to address the problem that avoids levying VAT on education, creates no additional obstacles to parents sending their children to private school, and spreads pupil migration over a longer period of time. The solution is to cap the recruitment of private school alumni in sectors where they are currently over-represented. A sensible rule would tie the proportion of independently educated in any sector to the proportion in the wider population. So instead of 65 per cent of senior judges having attended a fee-paying school, there would be a legal duty to bring that figure closer to 7 per cent. Obviously, these changes couldn’t be realised overnight and so the cap should be lowered in increments over time. Since it would be difficult, and perhaps not desirable, to stick rigidly to 7 per cent, there should be sufficient leeway to make the rule workable.

While there are those who would argue for a cap across both the public and private sectors, that strikes me as too illiberal. Limit it to government and public sector recruitment to ensure they better represent the public and allow private entities to decide their own hiring policies. The incremental nature of the cap and its application only to state-funded roles should reduce the chances of an immediate rush to transfer pupils to the state sector. There would still be every opportunity for the privately educated to dominate the private sector; they just couldn’t do so in the public sector any more.

A recruitment cap would do more than the blunt tool of VAT to weaken any link between private education and unfair advantage in attaining the most senior public jobs. It would also avoid some of the unintended consequences of that approach while still protecting parental choice. Parents should be free to choose whatever school they think best for their children but the state should act to prevent those choices from reducing the opportunities of others.