Poor teachers and inconsistent standards are the root cause of poor discipline, says a new study. TIM ROSS reports

Ofsted inspectors have blamed bad teachers for the discipline problems that have hit some schools. In secondary schools where behaviour was an isolated issue, the cause was often pupils' frustration with the poor quality of teaching they received, the watchdog said.

Too often, children did not find their lessons motivating enough, while some teachers failed to implement school rules on behaviour, according to the Ofsted study.

The National Union of Teachers condemned the comments, which it said marked a return to "the bad old days" of Chris Woodhead's controversial reign as Ofsted's chief inspector.

In a new report on behaviour in English secondary schools, the watchdog said teachers could improve discipline quickly if they gave "more varied and interesting" lessons.

Low-level disruptive behaviour, such as chatting in class, would be reduced if children worked more independently and were more motivated to study.

A coherent approach to improvements across the whole school was key, inspectors said.

The report went on: "The schools where behaviour was identified as an isolated weakness also realised that making improvements on a wider front was essential.

"In most cases, the behaviour issues in these schools stemmed from students' frustration with unsatisfactory teaching in a few classrooms, and a curriculum that did not motivate a vocal minority, as well as some staff not consistently implementing the school's guidance on managing behaviour."

Ofsted's verdict came 24 hours after a study from the IPPR think-tank said Britain's teenagers were among the most unruly in Europe.

The NUT said inspectors were wrong to blame teachers.

The union's general secretary, Steve Sinnott, said: "It is difficult to understand how Ofsted has come to this conclusion when it does not measure the quality of teaching during inspections.

"This smacks of a return to the bad old days of assertions by the then chief inspector which he could not substantiate."

He added: "Bad pupil behaviour is not determined by a single factor.

"Frustration at a curriculum is not an excuse for disrupting lessons and Ofsted is wrong to suggest that it is."

Schools can improve discipline by shutting unruly children in a so-called "sin bin" on site rather than sending them home, Ofsted also said.

Depriving pupils of their liberty to see friends at lunchtime, or attend normal classes, is not popular among youngsters, but parents like the idea, inspectors said.

Rewarding children for good behaviour with a school lottery ticket also reduced discipline problems.

Ofsted highlighted the ideas in a report on improving behaviour in England's secondary schools.

The inspectors said: "Schools held their nerve when exclusion rates rose as firmer and more consistent disciplinary arrangements became established.

"Some used internal exclusion rooms rather than excluding students from the school site.

"Many parents liked this, but not all of the students did!

"Internal exclusion meant that the students' work was supervised and less time was lost from learning.

"It also meant that students missed seeing their friends, especially at break and lunchtime."

Other schools ran reward schemes, offering pupils tickets for a school lottery.

"Students were consulted about the rewards they would value," the report said.

"Some reward systems involved the added excitement of receiving tickets for a lottery in school, with the chance, albeit small, of more substantial prizes."