Secondary teaching is undergoing a “seismic change” as young women step into the shoes of middle-aged male teachers approaching the age of retirement.

Women will soon be as numerous in secondary schools as they are in primaries, where they make up 84 per cent of the teaching staff.

Three quarters of new teachers are women and they are slowly replacing the 32 per cent of male secondary teachers who are aged over 50 and nearing retirement.

In the past 10 years, the proportion of secondary female classroom teachers has steadily increased from 54 per cent to 58 per cent, official figures show, and that increase is expected to continue apace.

Manchester University research, commissioned by the NASUWT teachers’ union, has found that the teaching profession is in the middle of a “seismic change”. But, in effect, women are still discriminated against. For instance, they often lose additional responsibility payments when they return from career breaks caring for children.

The report calls for an investigation into the impact of a female-dominated secondary workforce on pupils and their learning. One of its authors warns that men vanishing from teaching will deter boys from entering the profession.

“The jury is out on whether the predominance of women in the workforce affects the quality of boys’ learning, but it certainly does send a message about men and women’s professional roles,” said John Howson, a recruitment expert and one of the study’s co-authors.

The Training and Development Agency for Schools (TDA) has said campaigns to attract more men into teaching are beginning to have an impact.

“Both male and female authority figures play an important role in the development of young people,” Graham Holley, the TDA’s chief executive, has said. “We want the teaching workforce to reflect the strengths of our diverse society.”

Although the TDA has tried hard to attract more male teachers, its own research has failed to offer convincing evidence that they are vital to boys’ education. YouGov research for the agency showed that less than a third want more male teachers. Only 28 per cent believed men understood them better or could be relied on for advice.

Chris Keates, NASUWT general secretary, said that despite the fact that women formed the majority of the school workforce, they were still being unfairly treated.

“Sexism and gender discrimination are clearly alive and well and being presided over by governing bodies and local authorities,” she said.

Head with a hand in classroom practice

Rachel Macfarlane was still in her twenties when she became a secondary deputy head, and 35 when she first became a head.

Just five years later, she is in her second headship at the 900-pupil Walthamstow School for Girls in east London.

She felt she had suffered very little sexual discrimination in her 18 years’ teaching, but recalled a job interview during which one of the interviewers suggested that it would be better if she had worn a business suit, rather than the black jacket and smart scarlet skirt with white dots that she was wearing.

“I don’t think a man would have got similar comments,” she said. “Unsurprisingly, I didn’t get the job.”

Ms Macfarlane likes to keep her hand in at class teaching. She spends seven hours a fortnight teaching RE and history. “It’s a myth that once you become a head you lose touch with students,” she said. “You can get that buzz from interacting with students by teaching classes, but also by being out and about in the school as a head.”

She chooses to work up to 75 hours a week, but compensates by awarding herself good holidays. This summer she has planned two weeks’ island-hopping in Greece.