Teachers are being subjected to “derogatory sexualised” terms, as well as violence and threats by pupils in the classroom, a union conference has been told.

The NASUWT union’s annual conference heard that teachers have witnessed a “deterioration” in pupil behaviour over recent years, with many staff “struggling alone” with extreme cases in the classroom.

A motion passed at the conference condemned schools and colleges who claim that “unacceptable” pupil behaviour is just “part of the job”.

It also noted that teachers are often left with no access to appropriate support as “many school and college leaders do not receive adequate training” in how to deal with challenging student behaviour.

Wendy Exton, a member of the union’s executive, said: “We need to reclaim our classrooms, but we cannot do it alone.”

She told the conference: “Today, we have to deal with many of society’s problems in schools, issues with drugs and violence, knife crime, county lines that spill over into our classrooms. These crimes often go unreported as schools are afraid of the repercussions.”

Ms Exton said a culture had emerged where any blame for poor behaviour is taken away from the student and a variety of excuses are made – from “living on a council estate to trauma and even lack of tobacco”.

She added: “Today’s behaviour directed to us as teachers include not only vile language, but derogatory sexualised terms, threats to ourselves and our families, and indeed, violence itself.

“In classrooms, many staff are struggling alone with extreme behaviours,” Ms Exton added.

A survey of more than 4,700 NASUWT members suggests that 38% have been subjected to verbal abuse from students in past year, while 10% have received threats of physical violence from pupils during the same period.

The poll found that 6% of teachers have been subjected to physical violence by pupils in the last year.

The motion applauded NASUWT members across the country who have successfully balloted to take industrial action to refuse to teach violent pupils.

Rosemary Carabine, a member of the union’s executive, said: “Why should a teacher, or a group of teachers, feel they can only feel safe at work, or make a difference in their workplace, by using grievance procedures, or having to resort to collective industrial action to stop the threats or aggression that occurs for some on a daily basis?

“How many more disciplinary, capability or such procedures do we allow some of our members to go through because they are perceived to be not dealing with the unacceptable and extreme behaviour before we say enough is enough?”

Gary Upton, a member of the union’s executive, suggested a lack of funding had led to support staff cuts, larger class sizes and less targeted training which has made it harder for teachers to tackle pupils’ poor behaviour.

He said members had experienced “discriminatory” and “bad” language from pupils, as well as theft and damage.

“In so many cases, it’s the teachers that have to take time to reflect and think about what they could have done better. The reality being there is simply no money to train them in any other way,” he said.

Delegates voted for the executive to lobby employers and governments to ensure that teachers and headteachers receive appropriate training on behaviour management issues.

They called on the executive to continue to support members “using all appropriate means” where they face “unacceptable” pupil behaviour.

Dr Patrick Roach, NASUWT general secretary, said: “The NASUWT is unequivocal that no teacher should be expected to put up with any form of verbal or physical abuse, whether in the classroom or online.

“The union is continuing to take steps, up to and including industrial action and refusal to teach ballots, where members report to us that serious pupil indiscipline or abuse is going unchallenged by their school.”

A Department for Education (DfE) spokeswoman said: “In no circumstances should teachers be subjected to abuse simply for doing their jobs.

“We are taking forward ambitious plans to improve behaviour and discipline in schools, including our £10 million behaviour hubs programme designed to model and share exemplary practice, making behaviour management a core part of early teacher training and improving our guidance for schools to ensure it is clear and consistent.”