Who’d be a politician these days? You can’t mutter a spontaneous sotto voce comment during a conference speech without someone saying they eavesdropped. You can’t rip off your shirt on holiday without the media speculating about whether you shave your chest. You can’t even enjoy a relaxing game of croquet without the paparazzi sticking their long-range lens in.

Politicians are locked in a world of short-termism that is at odds with school life. Theirs is a career punctuated by the recurrent risk of rejection: losing your seat at the next election is likely to focus your mind on quick-fix successes underpinned by a spin culture that weaves a candyfloss ball of good news out of any initiative.

We do some of this ourselves, of course. Watch any head take over a school and you will usually see a succession of quick hits: a clampdown on uniform, a new look to the newsletter, hasty refurbishment of public parts of the school.

These are signals that we have arrived. They establish our credentials for effecting change at a deeper level. If we can get students looking smarter and arriving on time at lessons, the logic goes, then we can start to tackle the deeper aspects of the culture. And that’s the key word: culture.

Whether in a school or a yoghurt pot, cultures take time to grow, and time is what politicians so often deny us.

As Tony Blair finishes his last Labour conference as leader, few doubt that his impact on education has been remarkable and beneficial. We are unlikely ever to see such sustained levels of investment again, such commitment to renewing the once-dilapidated state of school buildings.

Mr Blair delivered the now commonsense notion that teachers should spend as much of their time as possible on planning, teaching and assessing, rather than queuing at the photocopier and doing endless cover for absent colleagues. We have seen a recognition that standards of numeracy and literacy - the building blocks of a humane education - had been allowed to fester for 50 years and had to be addressed.

But politicians’ lust for short-term fixes has blighted progress. The obsession with league tables undoubtedly prevents all but the boldest schools from genuinely innovating, or risking the removal of our students’

curriculum strait-jacket and giving them a different learning diet.

There’s the nutty idea of Ofsted giving a school in special measures 12 months to improve or face closure. Surely no one still believes a failing school can be genuinely turned around in a year.

There were the teaching and learning responsibilities. The old management allowance system was creaking and in need of renewal, but who hit on the wheeze of insisting it be done in a matter of months, reducing all but the most robust of schools to a hothouse of unhappiness?

Then there was the quick-fix ban on junk food, announced before its implications could be discussed and before schools could educate their pupils about the changes. So we see misguided South Yorkshire mothers becoming a volunteer delivery team of an alternative meals-on-wheels service, stuffing bags of chips through railings into the clutching hands of pupils at schools which have not had time to win them over. There’s the mad-cap U-turn on modern languages. No sooner had pupils been set free to choose whether they wished to continue their studies than Jacqui Smith, the schools minister, was rustling up targets to rein in the desertion from the subjects.

It’s not that schools don’t want change. In fact, I suspect we want to embrace deeper changes that will make schooling into something relevant for the 30 per cent of pupils for whom much of school life can be deeply demotivating. But you don’t create sustained change through quick fixes.

Most parents would trust us on this. I suspect they would like our attention to be fixed on constantly improving their children’s learning and welfare. Instead, they note our distracted gaze as we brace ourselves for the next volley of short-termism that’s just been lobbed out of Westminster.

Geoff Barton is headteacher at King Edward VI School, Suffolk