Many migrants come to the UK to work
The number of migrants coming to the UK for a year or more has risen to a record level, figures show.
Between mid-2006 and mid-2007, 605,000 long-term migrants arrived, up from 591,000 in the previous 12 months, said the Office for National Statistics.
The UK's population is growing by about a million every three years, also due to a rise in births, the ONS said.
About two-thirds of the increase in births were accounted for by women born outside the UK.
As of mid-2007, the UK population was almost 61 million, an increase of 388,000 from 2006.
It is rising despite a record level of emigration - in 2006/7, about 406,000 left the UK.
On average, that means about 1,650 are arriving in the UK each day, compared to 1,100 leaving.
UK Independence Party MEP Godfrey Bloom said the figures proved Britain did not have "proper" border controls.
He said the increase in the number of long-term migrant workers "belies the prime minister's promise of 'British jobs for British workers'".
There were 187,000 more births than deaths in the 12-month period.
Statistics show that the number of babies with foreign-born mothers has almost doubled in the last decade, from 84,497 in 1997 to 160,340 in 2007.
In some cities, including London, Slough and Luton, more than half of babies have mothers born overseas, and in the London borough of Newham the figure is 75%.
Guy Goodwin, from the ONS, told the BBC: "Effectively these are yesterday's migrants, as well as today's migrants, contributing to this high level of population growth."
Mr Goodwin said that a few years ago the contribution of births to population growth was actually falling, but now that trend has been reversed.
"There are two main drivers [for that]," he said.
"One is an increase in the fertility rates for both UK and non-UK born mums, but also it's because recent migrants have changed the number of people in that age band - child-bearing age."
Shadow home secretary Dominic Grieve accused the government of failing to manage Britain's immigration system.
"With births to foreign mothers becoming such a large driver of population growth, it is vital that immigration levels are set taking into account the ability of our schools, hospitals and other local services to cope," he said.
"With the number of migrants arriving from the new EU countries now approaching one million, the government's estimate that a maximum of just 13,000 migrants a year would arrive from these countries is woeful.
"Labour must realise that immigration can benefit the country, but only if it is properly controlled."
However, a Home Office spokesman said the government was "carrying out the biggest shake-up to the immigration system for a generation".
He said: "Centre-stage is our new Australian-style points based system which means only those we need can come here to work or study.
"Migrants contribute to the economy, putting more into the exchequer purse than they take out.
"So it is vital we take the social impact of migration into account when we make migration decisions.
"That's why we set up the Migration Impacts Forum (MIF) to provide independent advice to the government on how migration affects public services and local communities.
"We will also ask migrants to pay a little extra towards a fund of tens of millions of pounds to help services deal with the short-term pressures of migration."
The figures also show that asylum applications fell to 5,720 in the second quarter of this year, down from 6,595 in the first.
Donna Covey, chief executive of the Refugee Council, said that could indicate a worrying trend.
"If the low numbers of asylum seekers to the UK were the result of the world becoming a safer, more peaceful place, then we would have something to celebrate," she said.
"As it is, we have real concerns that people who need our help and protection are not able to get here to access it."
A second set of figures released by the Home Office on Thursday showed that the number of East European migrants coming to the UK to work has fallen to its lowest level since EU expansion in 2004.