Two-thirds of new babies in London have at least one foreign-born parent, figures show.
In some areas more than four in five newborns has a mum or dad born overseas.
The rate is below half in only six of the 32 boroughs in the city, which attracts a flood of immigrants a year.
Nationally, one in four babies has a parent born outside the UK, the Office for National Statistics reveal.
Former Labour minister Frank Field, of the Balanced Migration group, said: “We need two hurdles for immigrants.
“One to decide whether they can come here to work and a second to decide whether they can settle down, get citizenship and start a family.”
The statistics show 86,111 of London newborns in 2010—or 64.7 per cent—had at least one foreign-born parent.
The figure was highest in Newham (84.1 per cent), then came Brent (81.9) and Westminster (81.2).
Campaign group MigrationWatch said the “extraordinary” statistics showed London had been “changed beyond recognition.”