“Posh brainbox excluded by jealous plebs” screamed the Sunday Toff last weekend when it broke the story that the headteacher of one of Britain’s top private schools is not qualified to teach in the state sector.

Well not quite. But there was no doubt that a large section of the press was outraged by the General Teaching Council for England’s ruling that Tristram Jones-Parry, cannot take a state-school post without first gaining qualified teacher status.

The head of pound;15,204-a-year Westminster school “wanted to give a bit back” to society by offering his services as a maths teacher to a state school.

How on earth could the state sector reject the “unrivalled expertise”, columnist Melanie Phillips wondered in Monday’s Daily Mail. “This small but startling vignette sums up the terrible malaise that grips our education system,” she added.

Critics’ anger was fuelled further when it emerged that David Wolfe, a former professor in physics who has contributed experiments to the international space programme, had been told that he needed a maths GCSE if he wants to continue to teach physics to pupils at the Royal Grammar school, High Wycombe.

Not everyone was so upset, however.

Chris Keates, acting general secretary of the National Association of Schoolmasters Union of Women Teachers, accused critics of losing their sense of proportion. “I find it difficult to understand why the state sector is apparently being criticised for seeking to maintain high standards of entry to the profession.

“Presumably, the indignation being expressed at Mr Jones-Parry’s rejection by the GTCE stems from an automatic assumption by some that teachers in independent schools are of better quality and are better qualified than their state-school counterparts.”

But those attempting to dismiss critics as “posh people annoyed that they have to abide by the same rules as everyone else” have a second charge to answer. Not only has the state system apparently rejected an experienced maths teacher, but it is desperately short of people to take his place.

There has been a net loss of 3,400 qualified maths teachers since 1996. And more than a quarter of those teaching maths have no more than an A-level in the subject.

So shouldn’t the Government, GTCE and Teacher Training Agency be doing all they can to attract maths teachers?

Cutting red tape is surely more efficient than handing out pound;4,000 golden hellos to new recruits.

Sheila Ireland, head of Malet Lambert school language college in Hull, said: “I am sure he would be welcome at many schools. Maths teachers are in very short supply. It’s very, very sad that all that experience counts for nothing. Sometimes it’s political correctness gone mad if an experienced teacher can’t get a job.”

But the Government insists it has made efforts to make it easier for people to move into the state sector. Recruits to the on-the-job graduate teacher programme do not earn a full teacher’s salary. But they are paid as unqualified staff and can complete their training in as little as three months, although the normal period is a year.

Cynics have also been quick to point out that if Mr Jones-Parry really wants to put something back without training, he could choose to work as a high-level teaching assistant. Or he could work as an unqualified teacher, who in inner London can earn up to pound;25,000 a year.

Nevertheless, Carol Adams, GTCE chief executive, now says she would like to see a dedicated route into teaching for those who have extensive teaching experience in independent schools.

In fact, according to the TTA, such a route already exists, although it is so little known it does not even appear on the agency’s website.

Unqualified teachers with substantial experience can qualify without completing a minimum time period if they convince assessors they have the necessary skills. This involves classroom observation as well as evidence of their previous work. Last year out of 40,000 people in teacher training, 84 used this route.

But experts say that it must not just be rubber-stamping.

When the rules of the GTP were drawn up it was decided that all unqualified entrants wanting to gain QTS would have to complete at least three months’ training.

John Howson, recruitment expert, said this was because even applicants with extensive experience in the private sector are likely to have gaps in their knowledge.

“If you want someone to put a window in your house, they now have to be professionally qualified. It is right-wing nonsense that anybody can teach in state schools. There is no way we should be going backwards at a time when other professions are recognising the importance of qualifications.”

As headmaster of Westminster school, Mr Jones-Parry would not have come across many children with special needs or have had to follow the national curriculum, he added.

Even Mr Jones-Parry’s supporters echo those concerns.

Sheila Ireland said: “I am sure he will find it very, very difficult. One thing I would have thought he would have been used to is total parental support. You don’t always get that in the state sector and it makes teaching and managing children very difficult.”

Leader 22

Graduate teacher programme

* Trainees need a UK bachelor’s degree (or equivalent) and GCSE grade C or above (or equivalent) in maths and English. For primary teaching, candidates born on or after September 1, 1979 also need GCSE grade C or above (or equivalent) in science.

* Trainees must be employed as an unqualified teacher.

* The school pays a salary at the rate for an unqualified teacher.

* The Teacher Training Agency pays a grant of up to pound;13,000 towards employment costs and pound;4,000 to cover training.

* The programme normally takes one year. Trainees with teaching experience may be able to complete it in less time. The minimum is three months.

Assessment-only route

* Introduced in 20001.

* Graduates only.

* Intended for experienced teachers who have been teaching for some time but do not have Qualified Teacher Status.

* There is no training.

* Candidates are recommended for QTS on the basis of the submission of a professional development portfolio.

* They are also assessed in the classroom.

* No minimum time limit.

* TTA information line: 0845 6000 991 (0845 6000 992 for Welsh speakers).

NQT says

Samantha Fellowes, a newly-qualified chemistry teacher at Rosebery high school in Epsom, Surrey, said: “My PGCE prepared me massively for teaching.

I had no experience before that. I wouldn’t have wanted to go into a job like teaching without that. But if someone has been doing the job for years, you need some way of checking they’re up to standard. He (Tristram Jones-Parry) will probably need a crash course in behaviour management too.”

Head says

Penny Lewis, head of Allerton high school in Leeds, taught for four years in an independent school before switching to the state sector. She said: “I was appalled - it’s bureaucracy gone mad. He (Tristram Jones-Parry) has relevant teaching experience, experience of working with young people, and it seems to me he has a real passion that he wants to give something back to the system.

“There are a lot of people going out at the top who just might be happy to encourage learning in their subject.”