As everyone knows, the government really, really wants to bring back selective schooling. This has led to a fierce debate about the merits or otherwise of grammar schools. But few have noticed that the reintroduction of selection is a twin-track strategy. Ministers also plan to compel independent schools to provide “fully funded bursaries” for poorer pupils. The government says the number should be “considerably higher” than now.

We do not have to guess how this will work out. Post-war history is littered with attempts to force private schools to open up places to a wider clientele. Over many decades, both Labour and Conservative education ministers - including Rab Butler from 1941-45, Anthony Crosland from 1965-67 and Mark Carlisle from 1979-81 - spent much energy on the issue.

Ambitious but unsuccessful

Three main attempts were made. The first occurred during the Second World War, arising from a desire to scrub away society’s divisions. An official committee under Lord Fleming recommended top independent schools should devote one-quarter of their places to state-funded bursaries. Within a few years, thousands of children were benefiting. But growth stalled. In 1952, TES wrote that the plan was going “into storage”.

In 1965, Harold Wilson’s government set up another committee, known as the Public Schools Commission, to look at the question anew. This time, the recommendation was that top independent schools should free up half their places for taxpayer-funded bursaries. The plan may have been twice as ambitious but was not even half as successful. Very little happened in response.

Two decades on, the idea got rocket boosters. On coming to office in 1979, Margaret Thatcher established the Assisted Places Scheme, which paid for children to attend independent schools. By the mid 1990s, 30,000 pupils were receiving support and John Major promised to double the number. But Tony Blair won the 1997 election and closed the programme down instead.

When set against other educational priorities, bursary schemes offer exceptionally poor value for money

There were some big differences between the three initiatives. For example, the Fleming report and the Public Schools Commission focused on boarding whereas the Assisted Places Scheme covered the cost of day schooling only. A new version will no doubt have some features all of its own. But all three of the past initiatives failed, and for the same three reasons.

The first problem is that it is much more expensive to educate someone at a private school than at a state school. So, when set against other educational priorities, bursary schemes offer exceptionally poor value for money. This is true irrespective of whether the money comes from government or private sources. Work by the Boston Consulting Group showed private school bursaries were the single least cost-effective social-mobility intervention of all those they had tested.

The second issue is that no one has ever devised a fair way of determining which pupils should benefit. Should it be the most intelligent children? Or those from the most disadvantaged backgrounds? Or the all-rounders? Professor Sir David Watson, who was the principal of an Oxford college before his untimely death in 2015, won a Fleming bursary at Eton College because a housemaster was looking for someone who could sight-read on the piano. No wonder Sir David Eccles, education minister in the early 1960s, queried “the transfer of boys from one system to the other on a basis of selection in which nobody knows what would be just or why”.

Third, there has generally been a lack of demand for bursary schemes from both independent schools and the disadvantaged families they are meant to help. The schools have tended to back them when they have lots of empty spaces - as during the Second World War - but not when they are full. And when subsidised places have been available, they have been snatched by middle-class families. One major study of Assisted Places, published in 1989, found “no evidence so far that the main beneficiaries have been from the target groups originally envisaged”.

Carbon-copy mistake

All this explains why, in 2011, the Charity Commission lost a legal action brought by private schools. A tribunal said the commission was putting too much focus on bursaries and too little on other initiatives when deciding if schools were keeping to their charitable objectives. The government is now making a carbon copy of this mistake in threatening to force independent schools to offer more bursaries in return for their charitable status.

This is evidence-free politics. It is unlikely to work even on the government’s own terms. There must be a point beyond which our most successful private schools are not prepared to go when it comes to sacrificing their autonomy, even if it means giving up charitable status.

It would be incorrect to claim bursaries have never benefited anyone. Five years ago, Radio 4 tracked those who had won bursaries to Winchester College in When Wesley Went to Winchester, and many were very grateful. But policymakers and schools with charitable status must show they are using their fixed resources in the most efficient and effective ways. The new bursaries proposed in the government’s Schools that Work for Everyone consultation document fail this crucial test.

A decade ago, David Cameron said debating grammar schools was like “splashing around in the shallow end”. In that case, debating bursaries at independent schools is like dipping a toe in the ocean. Even if every private school in the country - good and bad, poor and rich - made 10 per cent of their places entirely free from 2017, it would still benefit only around 5,000 children each year. That is under one in a 100 children. So we are entitled to ask, “What about the 99 per cent?”

Nick Hillman is director of the Higher Education Policy Institute and has written about independent school bursaries for Contemporary British History, History of Education and Higher Education Review