The man in charge of London's schools has rejected claims that the capital's schools are under-performing.
Diane Abbott has been critical of colleagues' school choices
London schools czar Tim Brighouse spoke out as Labour MP Diane Abbott talked about her decision to send her son to a private school instead of a comprehensive.
Ms Abbott said her decision was "indefensible" and "agonising" but she took it to help her son.
At her local schools in Hackney, only 9% of black boys got five good GCSEs, she said.
Professor Brighouse says MPs' fears about standards in London schools are based on myth, not reality.
A new study to be published later this year would show that children at schools in London did better than schools with similar intakes in other parts of the country, he said.
Recently, the shadow home secretary Oliver Letwin said he would "go out on the street and beg" rather than send his children to state schools in Lambeth.
Professor Brighouse told the Times Educational Supplement it was "extremely sad" that people opted out of the state system.
"But it is no reason for them to talk down the achievements the rest of us are enjoying," he said.
"My experience in putting my children through urban schools is that they achieve in a vivid and rich environment that is determinedly improving its performance."