Women's liberation has been turned back 40 years by a new "raunch culture" that has led to "beauty pageants" being staged by student unions and pole-dancing exercise classes, teachers are expected to claim later.
A resolution due to be debated at the National Union of Teachers (NUT) annual conference raises fresh concerns that sexism and inequality is still shaping women's lives.
It says: "Far from being 'ironic' or 'empowering', the rise of the new sexism is damaging."
Schoolgirls are growing up in a world where it is normal for women's bodies to be seen as sex objects, the union is expected to say - and warns that this affects the way they see themselves and their place in society.
The resolution calls for the NUT to express its concerns about "the rise of what has become commonly known as 'raunch culture', where the old sexism of the past has been rebranded by big business".
The motion says: "In particular, the gains of the last 40 years in terms of women's sexual liberation are being turned back on women and girls in commodified form."
It adds that "pole dancing is sold as an 'empowering' form of exercise, and that the 'beauty pageants' of old have become a staple of student union life."
The resolution urges the union's executive to take action, including working to increase teachers' confidence in giving sex education lessons and campaigning to raise the profile of sex education in schools.
Speaking before the debate, NUT general secretary Christine Blower said: "There have been legal advances, but women still suffer significant inequality. Austerity is making women poorer and sexism still needs challenging to ensure that all women can achieve their full potential. Teachers are in a good position to empower girls and gay women to be self-confident and to reject stereotypes."
The resolution comes the day after delegates at the NUT's conference passed a resolution raising concerns that schools are not required to teach personal, social and health education - or sex and relationships lessons. This was resulting in many young people leaving education ill-informed or unaware of their rights or the relevant services, the union said.