Any school advertising for a “vigorous and dynamic” teacher, a “mature”

secretary or even a deputy head with “five years’ management experience”

could soon find itself in hot water.

New regulations against age discrimination make it illegal not just to advertise jobs with upper or lower age limits but even to imply a preference for candidates of a certain age.

Appointment panels could also be guilty of ageism if they reject older candidates because they cost more to employ than younger staff. This form of age discrimination has been going on at least since schools started managing their own budgets and remains widespread, according to a survey carried out by the Association of Teachers and Lecturers (ATL) this summer.

More than 1,000 members responded to the survey. Although 92 per cent said they had never faced age discrimination or been aware of it in their schools, 55 per cent claimed that their employers tended to recruit young people when they had vacancies.

Age discrimination in recruitment is usually covert. Sue Brown, who teaches in Northamptonshire, has been applying for permanent jobs since being made redundant 10 years ago and is convinced that her age and the experience that puts her at the top of the main pay scale count against her.

“I went for a job just before the summer holiday and was told by the head that I had more academic qualifications than he did, and I didn’t even get an interview,” says the fiftysomething maths and English teacher, who has set up her own private tuition business.

With half of teachers now over 45, concern about ageism is not confined to a disgruntled minority, as a recent survey for England’s General Teaching Council (GTC) revealed.

Asked which employment-related equality issues they most wanted the GTC to focus on, 67 per cent of the 3,665 teachers surveyed mentioned age, followed by gender (59 per cent) and race and ethnicity (46 per cent).

Although age came out as the most important equality issue for all groups of teachers, heads selected it least often, unlike classroom teachers - especially long-serving ones - who selected it most often.

Carol Adams, the GTC’s chief executive, believes this reflects a feeling among older classroom teachers that their work is not always valued.

Although a change in the law is not going to make that feeling suddenly go away, Ms Adams believes the new regulations will make a difference eventually.

“We think we are very fair in education, but there is still discrimination against older people in recruitment generally and that includes schools,”

she says. “However, these things are often quite subtle and difficult to prove. How do you know why you weren’t shortlisted? So I don’t think the legislation is going to have an impact on schools overnight, but it will gradually.”

Philip Lott, senior solicitor at the ATL, says schools will have to re-examine their assumptions about what people of different ages can and can’t do, as well as the “loose terminology” that is often used in job advertisements and recruitment literature.

He points out that the regulations allow employers to treat people less favourably because of their age - but only if they can show that this is “a proportionate means of achieving a legitimate aim”.

“Many appointment panels will say that it will be better for them to have someone who has done the job before,” says Mr Lott. “The question then will be, is it proportionate to impose that as a requirement when you have somebody who, for example, might be younger but has much potential and a proven track record in another area.

“So in recruitment, more attention will be necessary to the genuine requirements of the job rather than broad, rather blunt concepts of maturity, experience, youth or vigour.”

The new law will also have an impact on teachers’ retirement, especially in the independent sector, where many schools have insisted on retiring teachers at 60. The regulations set a national default retirement age of 65. Any employer who wants staff to retire earlier will need to show this is justified. The ATL, which has around 20,000 members in the independent sector, believes it will become very difficult for schools to continue to impose a retirement age of 60. The union will consider taking action against any that do.

All employees will have the right to request to carry on working beyond 65.

Employers don’t have to agree to these requests, but if they don’t at least consider them, the employee’s retirement will automatically become an unfair dismissal. With thousands of teachers opting for early retirement on reduced pensions each year, no one is expecting a flood of requests from those wanting to remain in the classroom into their late sixties, but there are bound to be some who want to, for financial reasons or because they love the job.

Patrick Grattan, chief executive of the Age and Employment Network, a pressure group backed by Help the Aged, predicts that growing numbers of people will want to work beyond 65 as life expectancy continues to rise and mid-life career change becomes more common.

“I would envisage that as we move to more flexible patterns of work, there will be many more people becoming teachers at, let us say the age of 48, especially women without good pension arrangements for whom both the desire and necessity to work longer will be very strong.”

WHAT THE NEW LAW SAYS

The Employment Equality (Age) Regulations 2006 make it unlawful to:

* discriminate against people because of their age - by refusing to employ, promote or train them - unless this can be “objectively justified”.

* indirectly discriminate on grounds of age - by applying policies, rules or selection criteria that disadvantage people of particular ages - unless this can be justified.

* harass people because of their age.

* victimise anyone who complains of age discrimination.

The regulations also:

* remove upper age limits for making unfair dismissal claims.

* provide for a new national default retirement age of 65 and make compulsory retirement below that age unlawful unless it can be justified.

* give employees the right to ask to work beyond 65.