England's schools are suffering from a “casual acceptance” of misbehaviour in the classroom, according to Ofsted chief inspector Sir Michael Wilshaw.
In a speech to launch the watchdog’s annual report today, Sir Michael is due to say that that disruption has been tolerated for too long, and that Ofsted will be cracking down on poor behaviour.
Low-level disruption in lessons and poor attitudes to education are stopping pupils from learning, and preventing the nation from moving up international league tables, he is expected to add.
Currently, around 700,000 children are being taught in schools where behaviour is not up to scratch, Ofsted figures suggest.
Sir Michael is due to say that there is a "poverty of expectation" in many schools that needs to be dealt with and "a culture of casual acceptance of low-level disruption and poor attitudes to learning”.
This is “a million miles away from the sort of cultures we see in some of the high-performing Asian countries", he is due to say.
The Programme for International Student Assessment (Pisa) international rankings, published last week, found that the UK’s performance in maths, reading and science had largely stagnated, while countries in East Asia surged ahead.
Sir Michael is expected to use his speech to call on school leaders who are failing to deal with naughty behaviour to create a "calm and respectful culture essential for learning".
Lessons should not be undermined by "background chatter, inattention and horseplay," he is due to say.
Last year, Sir Michael used his annual report to say that more than two million children were receiving a sub-standard education, with many youngsters facing a postcode lottery to attend a decent school.
Today, Sir Michael is expected to say that the "battle against mediocrity" is gradually being won, but that England is still a nation divided into "lucky and unlucky children".
Overall, eight in 10 state schools are now rated as good or outstanding by Ofsted – the highest proportion in the watchdog's 21-year history.
A Department for Education spokesman said: "Sir Michael is right – bad classroom behaviour is hugely disruptive to children's education. It means teachers can't teach and pupils can't learn.
"That is why a key part of our reforms is restoring discipline in schools and why we have strengthened teachers' powers to put them back in charge."
Malcolm Trobe, deputy general secretary of the Association of School and College Leaders said: "School leaders recognise that good behaviour in their schools is essential in creating a good learning environment.
“It was pleasing to note that of the large number of secondary schools inspected last term, 27 per cent were graded outstanding for behaviour – a clear indication of the importance that teachers place on good student behaviour.”