England's schools are suffering from a culture of "casual acceptance" of misbehaviour in the classroom, according to Sir Michael Wilshaw.
The Ofsted chief inspector warns that 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.
In a speech to launch his second annual report today, Sir Michael is due to say that this disruption and inattention has been tolerated for too long, and that Ofsted will be cracking down on misbehaviour in schools.
Currently, around 700,000 children are being taught in schools where behaviour is not up to scratch, figures suggest.
Sir Michael says 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".
A major report published by the Organisation for Economic Co-operation and Development (OECD), published last week, found that the UK's performance in reading, writing and maths has stagnated, leaving the nation's teenagers lagging far behind their peers in East Asian countries such as Singapore and Japan.
The UK failed to make the top 20 for any of the subjects, coming 26th place for maths, 23rd for reading and 21st for science, it found.
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 says.
Speaking on a visit to St Paul's Way Trust School in Tower Hamlets, east London, Sir Michael said: "We need to talk a lot more about the culture in our schools and the expectations we should have of our children.
"Too many of our schools suffer from poor behaviour and high levels of disruptive behaviour."
Last year, Sir Michael used his annual report to warn that m ore than two million children are still receiving a sub-standard education, with many youngsters facing a postcode lottery to attend a decent school.
He said there were ''stark inequities'' across England, with a child's chances of being taught at a good school far too dependent on where they live. In some areas children have a less than 50% chance of attending a school that is good or better, and it is not just those in poorer areas that are affected.
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".
Living in poverty is no longer an automatic predictor of failure at school, he suggests, and that many "lucky" children live in disadvantaged inner city areas and attend good schools.
Other "unlucky" children are poor youngsters living in reasonably rich areas in places like the Home Counties.
"Children from similar backgrounds with similar abilities but who are born in different regions and attend different schools end up with widely different prospects because the quality of their education is not consistently good," Sir Michael says.
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 (ASCL) 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% were graded outstanding for behaviour - a clear indication of the importance that teachers place on good student behaviour."