Bo's son is the poster boy for a private school system gone mad Anyone who has been to an expensive private school with an energetic "alumni outreach officer" will know the deal. The letters and the glossy brochures come regularly - one of them dropped on my door mat only the other day. Nick Clegg will have got the same letter and so will Chris Huhne, or Christopher Paul-Huhne, as he was known as a boy at Westminster School. So, too, will the singer Dido, the actress Imogen Stubbs and Martha Lane Fox. All of these distinguished people will have benefited enormously from their great good fortune to have been educated at one of the finest schools in the country. The attraction of our private schools has traditionally been in the excellence of the teaching, but no more, it seems. For the past 20 years or so, the great private schools of Britain, and some of the not so great ones, have been engaged in a demented arms race to outdo each other in facilities. In 1984, average yearly boarding fees in private schools were about £4,000. Today, many of them charge more than £30,000, roughly a threefold increase in real terms according to the Bank of England's inflation calculator. Private schools once offered a slightly superior version of a grammar school education. Many of them occupied lovely sites, but there was no special emphasis on lavish facilities. All this has changed, however. If you had the good fortune to go Eton, you might recently have written a cheque for the upgrade of the college's 15 tennis courts. St Paul's in west London, which has recently written to parents warning of an impending above-inflation fee increase, boasts on its website that on its 45-acre site, it has an art gallery and two (two!) theatres. The school has recently completed a "record-breaking" £75m fundraising drive. This, surely, is mutually assured insanity. When I was a boy at Westminster in the late 1970s, I was surrounded by the children of the middle classes. Of course, by any objective measure, we were highly privileged in the sense that the vast majority of parents in the country could not afford the fees. But who - apart from investment bankers and corporate lawyers - can pay £30,000 a year out of taxed income, before the hidden extras of the Ski Society's Easter break in Verbier? The answer, increasingly, is the children of the global super rich. Harrow School claims as its own Lord Byron, Robert Peel, Winston Churchill, Terence Rattigan, Jawaharlal Nehru and the actor Benedict Cumberbatch. To this list of famous old boys can now be added the name of Bo Guagua, whose place at the prestigious school north of London was apparently secured by Neil Heywood, another Old Harrovian. Mr Heywood was allegedly poisoned in his Chongqing hotel room in the presence of Bo Guagua's mother, wife of Bo Xilai, the ousted Communist party chief at the centre of the widening corruption scandal shaking the Chinese political leadership. There should be sympathy for Bo Guagua for his family's turmoil. He is certainly not accused of any crime, nor of any indiscretion beyond living lavishly and driving his Porsche too fast around Harvard, where he now studies after spending time at both Harrow and Balliol, Oxford. Yet he is unwittingly a poster boy for the new face of the English public school in the sense that his own world is entirely detached from the experience of middle class north London boys. The private school industry boasts that it is as ethnically "diverse" as the state sector. It says this to deflect criticism that it is elitist, but the diversity has come about largely because increasingly the core domestic middle class constituency is being priced out. Schools advertise themselves in the manner of luxury hotels or country clubs. My old school invites me to assist in "transformational change" towards its "exceptional future." For a tax-efficient donation of £100,000 I could become a "benefactor," rather like one of David Cameron's dubious guests for pasta suppers. With an eye on the expansion at St Paul's, it wonders if I might contribute to a £46m capital investment fund to build, inter alia, a transformational sports centre. Forgive me, Headmaster, but I'd rather not. My own two children are educated in north London primary schools. We have no complaints about the quality of their teaching, yet both spend their days in prefabricated classrooms. Neither has access to fives or tennis courts, nor indeed to proper sporting facilities. Of course, our public schools are private institutions, the best in the world, and by taking children out of the crowded state sector they save the Treasury money as they create a highly educated ruling class. If these schools want transformational sports facilities, or science blocks, or theatres, or music halls, that is largely their own business. Something troubles me in the latest glossy brochure on my door mat, however, for I realise that whether or not I write a cheque, I am already contributing to these fantastic facilities. As the headmaster makes clear, sign the cheque, fill in the Giftaid form, and hey presto, the government will top up your donation by 25 per cent from Treasury funds. Thus, parents who cannot, or will not, pay for their children's private education are nevertheless subsidising tennis courts at Eton and the picture gallery at St Paul's. I am reminded in the latest begging brochure that my old school was founded by Benedictine monks in 1179 as a charitable institution for poor boys. How far we have all come since then. The writer is a biographer