Few things make teachers feel more nervous than a sense of powerlessness. If seriously threatening pupils are thrust upon them, the hackles understandably rise. When the panel in the case of the expelled pupils at Glyn technology school ruled that expulsion had taken place too hastily, the subsequent national uproar came as no surprise. When independent panels focus exclusively on the child’s needs and ignore the feelings of teachers and other pupils, the result, as the Secretary of State suggested, can look like a catastrophic loss of common sense.

On the other hand, we should not forget that expulsion has serious implications for the child. One of my ex-pupils was permanently excluded from his secondary school for pinching a teacher’s bottom. Separated from his friends and not settling into his new school, he joined street gangs, truanted and ended up in trouble with the police. This boy was very naughty, but not dislikeable, suffering from the lack of a father. He needed containment, tough love rather than rejection. But then, on another occasion, I myself permanently excluded a disturbed five-year-old for attacking children with knives, and was under pressure from outside assessors to keep him. But exclusion in this case accelerated the specialist provision he needed.

But one question we should ask about every excluded teenager is: what were they like at primary school? As far as possible, a child’s behaviour should be anticipated. From the early years onwards we should get to know the depth of their problems. Despite the excellent principle of inclusivity, many teachers recognise that there are too many children who cannot be managed in mainstream classes of 30. It should come as no surprise that when they get older and impossibly unmanageable, it all seems too late.

Sir David Winkley is president of the National Primary Trust and former head of Grove primary, Birmingham