One in five schoolchildren is from an ethnic minority - almost double the figure a decade ago.
The annual school census reveals a Britain where one in eight pupils speaks a language other than English at home.
The record figures include more than 40,000 children from Eastern Europe who have enrolled at schools since the enlargement of the European Union in 2004.
The statistics emerged as the race relations watchdog warned that Britain's segregated schools are a "ticking timebomb".
The Commission for Racial Equality's director of policy said parents must stop sending their children to schools where most pupils come from similar religious or racial backgrounds.
Nick Johnson also suggested schools should be given more money to admit a racially mixed intake. He said: "We're in fear of turning into a mini-America with racially determined schools.
"Schools are where our children first learn how to get along with people from other cultures and backgrounds. Racially segregated schools prevent this from happening. This is a ticking timebomb."
Calling people "subhuman" for finding this kind of thing worrying is also a bit of a bar to community cohesion, isn't it, Nick? Perhaps you should take that up with your boss, eh?
His comments came as figures published by the Department for Education and Skills showed the biggest year- on-year increase in ethnic minority pupils for a decade.
They account for just under a fifth (19.8 per cent) of England's 6.5million primary and secondary pupils, up from 11 per cent when Labour came to power.
Meanwhile, the number of primary pupils alone who do not speak English as their first language increased by seven per cent from last year to 448,000 - or about one child in seven. Overall, it is around one in eight.
But the Commission for Racial Equality is concerned that there are not enough resources to integrate pupils from such diverse backgrounds. Mr Johnson said he was particularly worried about Tony Blair's controversial city academies and trust schools.
Well done Nick. Never miss a chance to push a leftist cause, no matter how irrelevant.
He added that some of these are using their extra freedoms to "cream off pupils from certain ethnic backgrounds or religions, thus ... increasing racial tensions".
The Conservatives said ministers had been caught off-guard by the increase in non-native English speakers in schools.
Tory education spokesman David Willetts said: "The Government has completely failed to keep up with the rate of change in our school population."
A DfES spokesman said: "The Education and Inspections Act 2006 placed a new duty on the governing bodies of all maintained schools, including faith schools, to promote community cohesion."
How wonderful. Of course, if successive governments had not embarked on the lunatic scheme of bringing people from all over the world to live together in one country, while at the same time continually undermining and belittling the native population and their culture, then we might not have problems with community cohesion on the scale that we do now. But that's wicked hate speech, and having read it, you must now say three Hail Trevs and genuflect repeatedly before a picture of Mandela, in order that your soul may be cleansed of the stain of "prejudice".