The non-white British population of England and Wales has grown from 6.6 million in 2001 to 9.1 million in 2009 – nearly one in six of the population.
There are now almost a million mixed-race people in the two countries.
The white British population has stayed the same since 2001; there has been an increase in births, but there has also been a similar number of people migrating.
The non-white British population has grown by 4.1% a year, adding up to 37.4% growth – 2.5 million – over the whole period. The only group to shrink is the white Irish population – down from 646,600 in 2001 to 574,200, due to falling birthrates and migration.
The mixed-race population is up nearly 50% to almost a million for the first time – up from 672,000 in 2001 to 986,600 in 2009. A third are mixed African-Caribbean and white, followed by Asian/white. The ONS said this was not a result of increasing birthrates but because "the population is mixing up more". Haringey, north London, has the highest proportion, at 4.4%.
In 225 local authority areas, more than 90% of the local population is white. That figure is highest in Wales and north-east England. The whitest borough is Blaenau Gwent in Wales, where 96.5% of the population is white British, followed by Copeland in Cumbria, where 96.3% of the population is white.
Brent, in north London, is the most ethnically diverse borough. Just over a third of its population counts as white British, with large mixed-race, Asian, black and Irish communities making up the rest. "Community cohesion is a priority," said Brent council leader Ann John, "As a result, Brent is a vibrant place to live and work, a beacon to the rest of the world."
But some groups expressed fears about the "changing face of Britain". Sir Andrew Green, of MigrationWatch UK, said: "If immigration continues at this rate, our population will hit 70 million within 20 years and immigrants will account for half of new households. We are already feeling the pressures on maternity units and schools.
This rise is part of Labour's legacy. Whether they meant to or not, they changed the face of Britain forever."
The figures, published for the third year running, are based by the ONS on fertility rates and death rates, and migration around the country and abroad.
