TEACHING unions have welcomed a landmark ruling by law lords backing the right of their members to refuse to teach violent and disruptive pupils.

The National Association of Schoolmasters and Union of Women Teachers, at the centre of the long-running court battles with two unnamed pupils, said the decision in the House of Lords would “give heart to every teacher in the country”.

The five law lords found unanimously that the union’s refusal to teach a teenage boy excluded and then reinstated by governors at a south London secondary school was a legitimate trade dispute.

They decided by a 3-2 majority that another pupil, whose exclusion from a Hertfordshire comprehensive was overturned by an independent appeals panel, had been properly reinstated in school even though he was being taught in isolation.

NASUWT general secretary Eamonn O’Kane said: “The decision is a total vindication of the stand consistently taken by the union over the years in giving total support to members when faced with violent or disruptive pupil behaviour.”

It came as the union revealed it had held 32 separate ballots over refusals to teach violent and disruptive pupils in 2002, virtually halved from 61 ballots in both 2001 and 2000.

Mr O’Kane said: “I think schools are taking firmer action than they did in the past. I think there is a greater willingness in the schools to take vigorous action when faced with disruptive behaviour because the Government has begun to take a similar stand on this issue.”

He said he thought the cut had also probably indicated a change in approach by independent appeals panels, but warned that it could just be a blip.

The Hertfordshire boy in the Lords case, now 18 and represented by Cherie Blair, the Prime Minister’s wife, was one of six students excluded in 2001 following a gang attack in school toilets which put a teenager in hospital.

Known in court as pupil L, he was taught in an 8ft by 6ft room with the glass door panel blanked out after returning to the school.

The law lords ruled last week that although social interaction was a highly important part of school life, the regime that pupil L had been taught under was a permissible response to the problem.

The London student - referred to as pupil P - was permanently excluded in 2000, aged 15, following physical threats and verbal abuse to staff and classmates.

His defence had argued that the refusal to teach was not a valid trade dispute. But all five law lords disagreed, finding that it did concern teachers’ terms and conditions.

National Union of Teachers’ general secretary Doug McAvoy said common sense had prevailed. The Association of Teachers and Lecturers also welcomed the ruling.