If you really know best, Mr Balls, why are there still so few good schools?

LAST Friday I stopped for fuel in a garage in Wandsworth.

"Didn't you use to work in education?" the cashier asked. I confessed that I had. "Well", she said, "things aren't getting any better, are they? My boy did really well at primary school. Now we've been told that the secondary school we wanted for him is full. They offered him a place in a lousy school miles from where we live. He doesn't want to go. We know he's not going to make any progress there." She seemed close to tears. "There's nothing we can do, is there?"

I commiserated and, muttering that it might be worth appealing against the decision, beat a hasty retreat. But the truth is that there probably is nothing she can do. Like thousands of other London parents who have received their children's secondary school place offers this month, she has no option other than to accept a decision she knows will damage her child.

Nearly half the children in Wandsworth, Southwark and Lambeth failed to secure a place in their preferred school. Three-fifths were rejected in Slough; two-fifths in Hammersmith and Fulham, Kensington and Chelsea, Richmond and Kingston upon Thames. Given these statistics, what can any parent do?

The problem, obviously enough, is one of supply and demand. London does not have enough decent secondary schools. Ministers disagree. Sarah McCarthy-Fry, the schools minister, wants us all to know that the system of transfer from primary to secondary school has been "transformed".

The admissions code, she told us last week, has been tightened to outlaw "unfair and covert admissions practices that disadvantaged low-income families". Ignoring the fact that the number of secondary school places has remained constant while the number of 11-year-olds has declined, she invited us to celebrate a slight increase (1.1 per cent) in the number of families nationally who received an offer from their first-choice school.

She is right in one sense, of course. The admissions rules have indeed been changed. They have now been made so complex that you need a law degree to have a hope of understanding what you are meant to do. A cottage industry has sprung up offering legal and educational advice on how to lodge a successful appeal.

Many authorities now use lotteries to pick the lucky few, so your child's future may depend upon the fall of the dice. Others force schools to admit equal numbers of children of different intelligence and from different social backgrounds. No school is permitted to exercise the slightest discretion in deciding which applicants are most likely to benefit from the education it offers. The state knows best and schools have no option but to conform.

The Secretary of State for Schools, Ed Balls, told the 2007 Labour Party conference that he wanted "to break down all the barriers to opportunity in Britain". Since then his government bulldozers have been in constant action. High- achieving comprehensive schools? Balls dismisses them as elitist institutions that discriminate against working-class parents and he forces them to accept more children from disadvantaged homes. Last week he warned a conference of headteachers that they had to do more for such children.

Independent schools? Bastions of privilege, which he would, no doubt, abolish if he could. Last week, for instance, the Standard reported his absurd attack on the decision of many independent schools to introduce the international GSCE instead of the ordinary GCSE examination. The independent sector knows that the GCSE now offers no intellectual challenge to its pupils, so it is turning to a more demanding examination. Balls dismissed this excellent educational decision as a "marketing strategy" to attract ambitious parents.

He has on a number of occasions made similarly hostile remarks about both grammar schools and faith schools. We have, it seems, a Schools Secretary who wants to destroy any educational institution that achieves excellent educational results. He cannot bear the thought that some children are cleverer than others or that some parents scrimp and save to send their children to private schools.

Meanwhile, he has sought to drag city academies back into the state fold because he believes that they should not have any advantage over any other state school. Their much-vaunted independence from local authority control - always over-hyped but the only thing that made them potentially different - has been limited yet further.

The whole point of Balls's new admissions code is to spread the misery of educational underachievement. All schools, he appears to think, will become good schools if all schools are rendered as bog standard as the state can make them.

Many London parents will ask themselves how it has come to this. Why are there not more decent secondary schools, after 12 years of supposedly radical reform? The obvious answer is that Balls is simply wrong. The way forward is not to bind schools yet tighter to Whitehall but to make them independent of the state: to allow them to determine the nature of the education they want to provide and decide their own admissions policies, in order to encourage a market in education in which schools compete to win the custom of potential parents.

This is what happens in the independent sector. Not every private school seeks to attract the brightest children. Independent schools recognise that children have different educational needs and set out their stall accordingly. Why should not state schools do the same? Why shouldn't the Government give every parent an educational voucher that is determined by their child's educational needs and allow them to use it in state or independent schools?

There are only three possible answers for why ministers avoid this option. The first is that all children have equal abilities and should be offered the same educational opportunities. The second is that we cannot expect disadvantaged parents to exercise an intelligent choice. The third is that the state does, as Mr Balls thinks, know best. None of these propositions are true.

You only have to look at the numbers of disappointed parents across London this month to know that the state does not know best. Twelve years of Labour centralism have not delivered higher standards in our secondary schools. I can't see Mr Brown changing tack now. I'd like to believe that Mr Cameron, if he wins the next election, might.

* Chris Woodhead was Chief Inspector of Schools in England 1994-2000 and is now chairman of independent schools operator Cognita.