Headteachers say they feel unable to exclude some of their worst behaved pupils because of a lack of space in pupil referral units (PRUs).
They also say that new exclusion regulations, which make schools responsible for pupils' education from the sixth day of an exclusion, are forcing them to take back misbehaving youngsters earlier than they would like.
Behaviour will be one of the main topics of discussion at the Easter teacher union conferences. When the NASUWT meets in Birmingham next week, teachers will argue that thousands of working-class pupils are having their education ruined by disruptive pupils. They will warn that the six- day rule, and pressure from local authorities to reduce exclusions, are putting staff and pupils at risk.
A straw poll of councils by The TES found 19 that said their PRUs were near capacity or, in some cases, over capacity. Eight said they had spare capacity, while seven others said they had created spaces as they were needed.
A spokesman for Shropshire County Council, whose one PRU is full, said: "Capacity is an ongoing problem, exacerbated by the exclusion regulations."
The NASUWT has published a blacklist of 32 of the country's worst-behaved pupils who were allowed back into classrooms last year despite wielding knives and scissors against staff and classmates, or making death threats and malicious allegations.
The union will vote next week to authorise strike action in schools where pupil discipline has broken down. Members will call for "punitive action" against school leaders or governors who fail to report assaults.
A survey of 800 members of the Association of Teachers and Lecturers suggested that one in 10 had been injured by pupils.
Mary Bousted, the union's general secretary, told its annual conference in Torquay this week that poor behaviour was driving away teachers at an "alarming rate": 65 per cent of them have considered leaving the profession.
"It is also damaging the chances of other pupils during lessons by causing major disruption," she said.
Jean Roberts, a primary teacher in London, said pupil behaviour was getting worse. She had permanent scars on her legs where she had been kicked while restraining pupils.
The National Union of Teachers will also call for more robust support for teachers who have been physically and verbally attacked.
The difficulties headteachers have excluding pupils may be exacerbated by two human rights law firms. They are jointly taking court action, arguing that heads should be allowed to exclude pupils only if their evidence of wrongdoing meets the criminal standard of proven beyond reasonable doubt.
In one case, a 14-year-old boy was excluded after being accused of dealing in cannabis; in the other, a boy was excluded for carrying a knife. Neither the cannabis nor the knife was found, and the lawyers are challenging the credibility of witnesses to the alleged offences.