Women teachers are missing out on fair settlements over pay and professional training in work, according to the UK's largest teaching union.
Many teachers gathering at the NASUWT's women's consultation conference in Birmingham raised concerns about what they called "the systemic unfairness" in how some schools had managed pay and performance.
The union said almost half of the attending teachers "had experienced discrimination in relation to pay or pay progression this year".
Some delegates also reported being hindered over access to professional development and training at work.
Chris Keates, the union's general secretary, addressing the conference, said: "The potential for discrimination and unfairness highlighted by our women members today is deeply worrying."
Keates added: "The NASUWT has consistently warned the coalition Government's reforms to the teachers' pay system, coupled with the increasing fragmentation of the school system and the lack of local oversight of schools, could increase the potential for discrimination to flourish and for schools to seek to deny teachers their statutory entitlements.
"These statutory entitlements are designed to support teachers to provide the highest standards of education to our children and young people.
"Schools which seek to flout the law in this way are undermining the professionalism of teachers and the entitlement of children and young people to be taught by a well-resourced and supported teaching workforce."