Schools should be allowed to access information held by the gardaí when deciding whether to allow students with serious records of anti-social behaviour into the classroom, the Teachers' Union of Ireland (TUI) believes.
Mr Paddy Healy, president of the TUI, said some of his members were being forced to teach students who had personally threatened them or their property, who had been in trouble with the gardaí, or who were involved in teenage gangs responsible for "mayhem and disruption" in certain areas.
The students in question range from 12 years of age upwards, but can be involved in such behaviour from as young as 10 years old, he said.
"The gardaí are extremely reluctant to give any official information on minors," Mr Healy said.
"But in extremely difficult cases where the child has already been criminalised and needs rehabilitation before admission, this would allow the school to insist on this before allowing them to enter the school."
In an interview with The Irish Times last week, the Minister for Education and Science, Ms Hanafin, acknowledged that some of those responsible for anti-social behaviour outside school at night end up sitting before teachers in the classroom the following morning.
Mr Healy, who has made the issue of school indiscipline a central theme of his presidency, said he was personally aware of instances where his members were physically threatened by students with long histories of anti-social behaviour.
These included an assault on a teacher by a former student wielding a wooden implement, and the admission by another student that he/she had stolen and burned a teacher's car.
"We also have recent cases in which the lives of teachers were threatened by students. Students have been found to be in possession of offensive weapons, including knives, pellet guns and catapults," he said.
"But the school is not entitled to official information from the gardaí."
However, the TUI president stressed that he was referring only to the most extreme cases of persistent anti-social behaviour.
The vast majority of disciplinary issues should be addressed in schools, without having to resort to obtaining information from the gardaí, he said.
The TUI is to hold a major conference for its members on the issue in December.
The TUI welcomed the decision by Ms Hanafin to investigate ways of addressing indiscipline in schools, Mr Healy said.
But the lack of dedicated units, both within schools and elsewhere, to deal with persistent offenders meant the behaviour of those students who were readmitted following suspension frequently deteriorated, he added.
"Within the school we want teachers and boards of management to be allowed to effectively implement disciplinary measures.
"There is currently an imbalance of rights between those who want to learn and who we can persuade to learn, and those who don't."