Fed up with taking a softly, softly approach to unruly pupils, the NASUWT hailed the traditional response: “Sit down, shut up and listen to me.”

But the National Union of Teachers (NUT) rejected calls for a “zero tolerance” approach to discipline in the classroom after hearing arguments that pupils need to be supported, rather than stigmatised.

Young teachers entered their first jobs with no idea how to handle even the most juvenile schoolboy pranks, such as the tapping of a pen on the desk, orchestrated coughing and circulated text messages, the union said.

But it was those seemingly minor incidents that led to more serious issues, including the problems with knives and other weapons highlighted by a teacher union survey at Easter.

At the height of the concerns this week, the Government announced that it would change the law to require all mainstream schools and academies to join behaviour partnerships, working together to provide education for excluded pupils.

Ed Balls, Children, Schools and Families Secretary, said 97 per cent of secondary schools were already in behaviour partnerships, but the remaining 3 per cent that were not co-operating were enough to undermine their effectiveness.

He was acting on the advice of Sir Alan Steer, the headmaster of Seven Kings High School in Ilford, who argued that schools had a social responsibility to take in problem pupils who had been excluded elsewhere.

But NASUWT members said young teachers did not know how to handle such problem pupils. Newly qualified teachers were being taught to build up a pupil, with 10 compliments for every criticism, said one - even if that positive reinforcement was about such trivial things as the child’s hairstyle.

Tim Cox, an NASUWT union executive committee member, said the constant low-level disruption often escalated. “It’s the tap, tap, tap of a pen on a desk, the orchestrated coughing, the refusal to comply with the simplest of requests, wearing coats and hoodies and sending text messages,” he said.

Earlier, a survey commissioned by the NUT found there was a core group of schools where pupil violence, poor behaviour and disruption was worsening.

The Association of Teachers and Lecturers also heard concerns that pupils were “upping the ante” with their often criminal behaviour in a high-stakes competition to join their friends in over-crowded and understaffed pupil referral units.

Teachers at the NASUWT’s conference in Birmingham this week applauded the “sit down and shut up” approach recalled by Suzanne Nantcurvis.

But NUT members voted overwhelmingly in support of a motion which focused on addressing deeper causes of poor behaviour. Sara Tomlinson, of Lambeth in south London, who tabled it, said measures such as metal detectors in schools would stigmatise pupils.

Speaking later, Chris Keates, NASUWT general secretary, said the applause recognised that sometimes teachers need to take a straightforward approach to discipline. “Sometimes you want someone to come in and say, ‘Sit down - there’s a lesson to be taught,’” she said.