After 10 years as a research chemist, Stuart Fieldhouse fancied a change of career. As he pondered his future, one advert kept catching his eye. "Use your head - teach" ran the slogan, so he thought he would. "They seemed to be specifically aiming those adverts at people like me. They didn't show some young lad, they usually showed a more mature person," he says. "I thought they were crying out for science teachers."
But towards the end of his PGCE course at Manchester Metropolitan University, he started to become concerned. As his fellow students began to get jobs, Stuart's applications came to naught. Six months after the end of his course, he is beginning to believe that it is no coincidence he is - at 36 - the second oldest in his cohort, and the only one without a permanent post.
"After a few interviews, I started noticing that they always seemed to be going for the 24-year-old," says Stuart, from Prestwich, near Manchester.
"A lot of schools have asked me back for supply, so I know I'm not a bad teacher, but it seems that every time I turn up for an interview I'm wasting my time."
Geoff Evans thought his engineering experience in the private sector would be welcomed in schools. He even got a pound;1,000 bursary to train as a secondary technology teacher. At 44, he was the oldest in his group at Liver-pool John Moores University - and he is the only one still without a job. "I think that is quite striking, even more so because ICT is a shortage subject.
"If there is a shortage of jobs, perhaps age becomes one of the factors they use to filter applications, throwing out the older candidates," says Geoff, from Liverpool.
"Maybe they think younger teachers are more malleable, but I've got the commercial skills and ethos they are trying to engender in schools. I thought they wanted to bring outside experience into schools, but that doesn't seem to be true in practice."
Malcolm Trobe, president of the Association of School and College Leaders and head of Malmesbury School in Wiltshire, says it would be wrong to say that age would count against someone.
But he adds: "It is perhaps true that it brings to the front of the mind some questions about adaptability and ability to fit into the culture of the school."
He says there are reasons why some heads may favour younger applicants.
"Where people have come in after having had a previous career, they have not always made the adjustment to teaching very well. We have had some extremely good people come in that route but we have had proportionately more issues with them than with people who come in relatively young."
He says evening commitments can put considerable pressure on the worklife balance, and the physical nature of being on your feet in front of a class for five hours a day can prove demanding, while some find it hard to adapt to the culture of giving a lot of your time, often with limited reward.
Against this is the breadth of experience that someone who has worked outside education can bring into school, he adds.
Teachers with experience outside the classroom can ask for that to be taken into consideration in setting their starting salary. In reality, though, it is likely to give them a maximum of one extra point on the pay scale, a salary of pound;21,195 for new teachers outside London in 20067, compared with Pounds 19,641 on the bottom rung.
Tim Andrew, the headteacher of Chesham High School in Buckinghamshire, says cost was unlikely to be a reason why older teachers find it harder to get jobs. But there may be questions over why they left their previous career.
"If I felt they were coming into teaching to get away from something else, I might wonder if it was going to work. It is a job where you have to make an emotional engagement, and if you don't, you might not be able to give the kids the buzz they need," he says.
John Howson, a recruitment analyst and visiting professor of education at Oxford Brookes University, says over-thirties are more likely to be settled and so may be restricted in where they can work. With the age profile of teachers skewed towards the 40 to 44-year-old group, some headteachers may also opt for younger candidates to balance their workforce, he adds.
"There are more people chasing jobs than there are jobs, and you will eventually get to the point where people don't believe the advertising," he says.
Jean Cook, 49, from Lincoln-shire, trained to be a music teacher after taking a degree following 12 years in the civil service, but three years after completing her PGCE, she is still relying on supply work.
"I thought they were crying out for teachers but in my NQT year, while I found I got an interview for almost everything I applied for, I never got the job," she says. "The majority of supply teachers I know are mature, because they can't get permanent positions. Maybe they think older people are a bit more set in their ways."
Meanwhile, Stuart Fieldhouse is still looking. "Maybe there is some prejudice against mature entrants, but if I had done this at 23 I would have been useless at it. Now, I'm much wiser," he says. "I absolutely adore teaching - though if they'd said, 'Don't bother going into it if you are over 30,' maybe I'd have had second thoughts."
Discrimination on age grounds is illegal, but schools may still be able to favour younger applicants for jobs, according to Richard Bird, legal consultant to the Association of School and College Leaders.
He says an employer can give preferment to a particular age group in order to plan to balance their workforce.
"At this point in time, the majority of teachers are well over 40, and therefore it is possible that schools could legitimately try to balance that by getting younger people," says Richard.
"You cannot discriminate on grounds of age, but you are allowed to plead justification for a sensible manpower policy."
But he says interviewers would be unwise to ask any questions in an interview which could, even indirectly, be used to conclude that discrimination may have arisen. One example may be asking if an older candidate was likely to have difficulty relating to children.
THE GENERATION GAP
Figures from the Training and Development Agency for Schools (TDA) show about 37 per cent of people starting initial teacher training to be secondary teachers in 200304 were over 30. The previous year it was 37.5 per cent, and in 200102, 35 per cent.
But according to figures from the Department for Education and Skills (DfES), only about 32 per cent of qualified secondary school teacher entrants in 200405 - the only year for which figures are available - were over 30. The gap between those who start training and those who get jobs suggests over-thirties find it harder to get jobs as teachers than their under-30 counterparts.
A spokeswoman for the DfES says: "At our request, the TDA encourages career-changers to train as teachers. There may be a number of factors, including location, which may influence whether they get jobs."
The department did not believe the figures showed a serious issue.