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 today.
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.
Speaking after the debate, Ms Blower said: "It is important for all children and young people to learn, in an age-appropriate manner, about respect for their own and other people's bodies and emotions.
"This is all the more important given the rising levels of pornography which is very much in the public domain. There also continues to be a high rate of sexual harassment and homophobic bullying in society at large, despite efforts in schools to address and reduce it.
"If schools do not have the time and are not encouraged to invest in this area of the curriculum, then some pupils will be left to struggle with issues that can seem insurmountable and they will miss the chance to acquire vital life skills."
A Department for Education spokesman said: "Ministers are clear about the importance of PSHE (personal, social and health education) - that is why it remains part of pupils' education. PSHE encompasses a number of different areas, many of which are compulsory.
"Beyond that it is right that teachers are given the freedom to tailor PSHE to the pupils whose needs they know best. We are funding the PSHE Association to demonstrate best practice in covering the subject.
"Sex and relationship education is compulsory in maintained secondary schools and it remains for primary schools to decide whether they want to teach it. All teaching of sex education must be age-appropriate and have regard to the Secretary of State's guidance."