Holiday advice for teachers: don’t tell strangers of a certain age what you do. You’ll be lectured on falling educational standards and poor teachers, then hear some home truths about discipline, including, probably, “The cane never did me any harm.” It’s possible the occasional thrashing did them no lasting damage - though it’s worth checking for a twitch or other sign of instability.

We (nearly) all went to school, so we are all self-professed experts. Government ministers indulge their moral certainty in similar style. They pursue personal crusades with the same tenacity as the holiday bore: unfortunately they also have the power to turn gut feelings into policy. We’ve seen examples in the past year with the English Baccalaureate, widening access to “elitist” universities, and synthetic phonics

One issue, “teaching schools”, troubles me. The proposal is that the serious business of training the next generation of teachers should be removed from the ivory towers of universities and put entirely into schools.

Of course schools must be centrally involved in teacher training: the most important element has always been teaching practice. Although my school doesn’t qualify for teaching-school status, we are happy to be a strategic partner in a number of bids.

Teaching schools may give the country what it needs in terms of future teacher supply. But why must they run the programme? The Government’s rather too public scorn for the old university-based PGCE is based on prejudice and ignorance.

I am fiercely proud of my 25-year-old daughter who, after three years’ post-university working in the City, decided she wanted to teach. She didn’t want to follow the graduate teacher programme route. She wanted a structured course with significant periods of classroom practice, but within the PGCE framework of reflecting on practice, learning about the bigger picture of educational purposes and philosophy.

I am awestruck by what she has done and learnt this past year. Her preparation for every lesson has been meticulous. She has soaked up the research on learning, behaviour, assessment and classroom management and put it all into practice: by comparison, my own preparation for teaching nearly 35 years ago was pitiful. Parental pride apart, I see a superbly prepared entrant to the profession.

Yet “learning on the job” is now to be the only viable way for teachers. The idea of chucking people in at the deep end apparently appeals to the baser instincts of British voters, suspicious of intellectuals, of those who think or question. But it is an assumption that is deeply flawed. Teachers without that year’s teacher training tend to adopt the style of teaching they experienced as pupils. In the independent sector, where qualified teacher status isn’t required, many heads nonetheless prefer candidates for jobs to come with a period of training under their belt. Though there are exceptions, PGCE or teaching BABEd graduands are invariably readier for the job than their rivals coming straight out of a degree or other employment.

Schools make a central and indispensable contribution to the effective training of teachers. They know what works, and what doesn’t. But they also have to deal with relentless government pressure and follow its shifting agendas. Moreover, their primary task is to teach children, so there is a risk of loss of focus, even mission drift, over time.

Capacity could become an issue: with an annual offer of #163;40-50,000 to teaching schools, I am doubtful whether an independent school like mine - acutely aware of the sacrifices parents make to pay fees and parsimonious in the way we spend them - could find the spare capacity to take the lead in a consortium. We cannot be alone in that.

Research and objective evaluation over time are the territory of higher education, better placed than busy schools both to plan and structure training programmes and to remind trainees of the theoretical and moral frameworks that underlie their vocation. To deny HE’s contribution to the process is narrow-minded and anti-intellectual. Fortunately, would-be teaching schools know this, and many included university departments as strategic partners in their bids, whose outcomes were announced last month.

This “forget all that theory and get on with the job” attitude betrays government’s low opinion of the real craft and challenges of teaching. We face a tragedy if, despite everything we have learnt about preparation and training, not least from international competitors, teachers are regarded - unlike brain surgeons, engineers and even computer programmers - as low-skilled technicians who can learn on the job and pick up a few necessary skills along the way. We should be very wary.

Dr Bernard Trafford is headmaster of the Newcastle upon Tyne Royal Grammar School.