Things are getting worse for women in the workplace. A government last year report found that 11 per cent of women reported being either dismissed, made redundant when others in their workplace were not, or treated so poorly they felt they had to leave their job. The risk that women will be discriminated against by their employer increases if they become pregnant. The number of expectant and new mothers forced to leave their jobs has almost doubled to 54,000 since 2005.

Women make up 74 per cent of the teaching workforce in state schools, so you could be forgiven for thinking that discrimination is not a problem in education - but you would be wrong. Only 65 per cent of primary and secondary headteachers are women.

Sexism is a particular problem in secondary schools. The figures are stark: only 38 per cent of the secondary school workforce is male, but men are appointed to 72 per cent of head posts. Only half of women teachers are promoted to assistant head and even fewer (44 per cent) get to be deputies.

Research by Education Datalab reveals how discrimination might work in practice in many schools. Even those female teachers who do achieve senior leadership roles are paid less than men with the same level of responsibility. Women are awarded smaller annual pay rises than men at all levels of seniority - and this gap is particularly large (almost £400) for female deputy heads.

Interestingly, women are a little more likely to achieve internal promotion to headship within the school they are currently working, but are far less likely to be promoted to headship in a different school. Women teachers’ professional worth, it seems, has to be seen up front, close and personal. Men are much more likely to have their talents rewarded through the more remote lens of the job application and interview process. It is not hard to see just how much more difficult it is for women to achieve promotion if their horizons are limited to their current school rather than, as for men, the schools in their region or nationally.

These hard facts are shocking, but they do not surprise me. I have been struck, many times, by my conversations with women teachers who have been teaching for some time. Typically over 50 years of age, they tell me tales of a double whammy of sexism and ageism, which results in highly discriminatory treatment meted out to them.

Gradually, incrementally, these experienced women teachers find that their previous good performance in the classroom becomes unsatisfactory. They are given unrealistic targets in their appraisal and find themselves, often very suddenly, subject to capability proceedings.

All of this unfair treatment is justified by their line managers - and by the school’s senior management team - by the drive to raise standards, however these are defined. The cult of youth, and of patriarchy, lingers long in too many schools’ professional cultures; it leads to women teachers’ worth being undervalued, their talents neglected and their promotion prospects diminished.

Girls share as unequal a position as women in schools. Recent research shows that nearly 25 per cent of girls report that they feel worried at school - compared with just 16.5 per cent of boys; approximately 24 per cent of girls feel that they do not belong at school, compared with just under 9 per cent of boys. Girls also feel that their teachers are less likely to know them well and would know the boys in their classes better.

Sexism in schools is a problem that affects women and girls. It is time that it was taken seriously - and then eradicated.

Mary Bousted is joint general secretary of the National Education Union @MaryBoustedNEU.

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