Almost a quarter of babies are born to immigrant mothers, an official breakdown showed yesterday.
It found that 24.7 per cent of children born last year have mothers who were born abroad – and that their numbers have doubled since the late 1990s.
The sharply rising numbers of babies with foreign-born mothers came despite an overall fall in births.
The figures produced fresh warnings to ministers that immigration rates must be brought down to avoid the growing threat of overpopulation in Britain.
Numbers of children born to mothers from outside the country have been growing fast in recent years as immigration has reached record levels.
In 1998 there were 86,456 babies born in England and Wales to mothers born abroad. These mothers are considered likely to be long-term migrants by statisticians.
Last year, the total had reached 174,400, according to the figures from the Office for National Statistics.
Over the same period, the share of babies with foreign-born mothers rose from 13.6 per cent to 24.7 per cent.
The rising proportion of children of migrant mothers is a result both of high levels of immigration and higher birthrates among newly-arrived families.
Last year, the ONS calculated that women born in Britain will average 1.84 children each during their lifetimes, while women who came to this country from abroad will have 2.51 children during their lives.
Immigration and higher birthrates are the greatest factor in pushing up population rates.
The ONS has predicted that the UK population will hit the sensitive 70million mark in 2029.
Alp Mehmet, of the Migrationwatch think-tank, said: ‘These figures confirm that action is necessary to bring down immigration levels and the Government have to get on with it.
‘Nothing that anyone has said in recent months has altered the prospect that there will be 70million people in the country in 20 years’ time.’
The breakdown of figures was published by the ONS yesterday in its final tally of births and birthrates in 2009. Overall, the number of babies born in England and Wales fell slightly from 708,711 in 2008 to 706,248 last year.
The numbers of babies whose mothers were born abroad went up by around 3,500, from 170,834 to 174,400. The three most common countries of origin of foreign-born mothers are Pakistan, Poland and India.
Around one in ten babies are now born to mothers from New Commonwealth countries, according to the ONS breakdown. In some towns with high numbers of immigrants, a majority of young children now have mothers who were born abroad.
In London around half of babies have foreign-born mothers. And in some London boroughs, such as Newham and Brent, around three quarters of children have mothers who were born abroad.
