Public discussion of independent schools is a bit like that on Roman Catholic schools. It slumbers on beneath the covers for a little while and suddenly, for no credible reason other than the occasional self-serving purposes of a newspaper opinion poll, it explodes above the surface. The latest episodic excitement emerged over the charitable status of private schools which, again, appeared to have no very obvious source except for the prompt provided by the Charity Law Reform Bill due to be launched in the spring and a few odd comments to Holyrood magazine by MSPs.

Charitable status is, of course, a clear subsidy for independent schools since it allows them to avoid paying business rates and VAT on some of their costs. Schools funded by the state in the interests of the Catholic or Episcopalian faiths also attract unique support from the taxpayer.

Whatever the arguments provoked by the impending legislation about what constitutes a “charity”, there will be little sympathy for private schools.

If the figures being bandied about on the effects of losing charitable status are correct, an average increase in fees of pound;170 per pupil a year for families willing to buy fee-paying education at pound;6,000 a child each session hardly looks like the start of frugal living. The impact on individual schools may be quite small: the head of George Heriot’s in Edinburgh made a telling point when he revealed that the school saves pound;120,000 by having charitable status, while it costs pound;625,000 to provide scholarships for non fee-paying pupils.

At the end of the day, the arguments about state and independent schools resemble those about public transport and the car. It is only where public provision is of high and reliable quality that there can be a real choice for consumers. It requires continuing investment to bring that about.

Meanwhile any move to make life more difficult for the independent school would not be worth the political candle - and would be as futile as trying to abolish the car.