London: Unruly children are copying the worst behaviour they see from footballers and celebrities on television, the Government's school discipline czar warned on Wednesday.

Sir Alan Steer claimed that abusive soccer stars fuelled violence in the playground while celebrity sex scandals encouraged teenage promiscuity.

In an interview, Sir Alan called for a ban on televisions in children's bedrooms to minimise the influence of popular culture on the young.

Parents should spend more time and less money on their children, and must be prepared to say "No" more often to their demands, he suggested. Sir Alan, the former head of Seven Kings High School in Ilford, was speaking as he published his final report for ministers into classroom discipline.

His study comes amid growing concerns over the breakdown of respect and standards of behaviour in schools and wider society.

As he launched his report at the NASUWT teachers' union conference in Bournemouth, Sir Alan stressed that most children behaved well.

The "vast majority" were a credit to their generation, volunteering and working hard, he said. But a minority disrupted lessons with low-level back-chat, while some had "major behavioural problems" which were of "considerable concern", he said. Sir Alan said that parents and other adults must set an example. "We as adults have a responsibility to children," he said. "If we behave in a certain way children will copy it. We have a culture where we are prurient. The sexual life of celebrities is all over the press and yet we wonder why youngsters are sexually active.

"If footballers are violent and abusive is it a surprise children are copying them?" he added.

"If one could wave a magic wand, wouldn't one want to abolish the television in the bedroom?

"I think it's a bit sad if we have families where they are not meeting and everybody is separating off to their own rooms and listening to their iPods or playing with the computer."

Most parents are not aware of the dangers of the internet, particularly how easily children can be exposed to pornography and other inappropriate material, he said. But parents have "prime" responsibility for ensuring children grow up knowing how to behave, he said.

"Most parents are doing an extremely good job. Where it falls down, I think, parents need to think about certain things and schools can do a lot to help. Parents often simply don't know what to do that's right."