One in four children born in Britain has a foreign mother or father, according to figures released yesterday.

A surge in migration has also helped to drive up the birth rate to a 26-year high. Live births last year increased for the fifth successive year, to 734,000, compared with 663,000 in 2002.

The 25 per cent foreign parent figure – for the year to July 2006 – compared with 20 per cent in 2001. Mothers born outside Britain had 21.9 per cent of births in 2006.

Statisticians at the Office for National Statistics (ONS) predict that the birth trends will continue for the next three to five years. A spokesman said that the figures reflected the cumulative effect of immigration over the past 40 years.

Provisional fertility rates for 2006 give an average number of 1.87 children per woman in England and Wales – an increase of nearly 4 per cent since 2005, when the figure was 1.80.

Yesterday’s figures show that births have increased as the number of people dying has fallen: the number of people aged 85 and over has hit a record 1,243,000. At the same time the number of people of retirement age rose by 1 per cent to 11,344,000.

The overall population of the UK rose 349,000 to 60.5 million in mid2006, the ONS figures show.

A major factor in the increase was immigration, which accounted for 55 per cent of last year’s population growth. At the same time, a record 385,000 people, of whom 196,000 were British citizens, moved out of the country. The number of UK citizens migrating in 2004-05 was 188,000, and the previous year 195,000.

The figures also show that an estimated 74,000 migrants from eight former Soviet bloc states which joined the EU in May 2004 arrived in 2005-06, and that 16,000 left.

Inward migration amounted to 559,000, of whom 468,000 nonBritish people included 149,000 from the EU and 179,000 from the Commonwealth.

Karen Dunnell, the national statistician, said that the population was changing rapidly, with an increasing flow of people in and out of the country and around the UK.

She admitted that one of the challenges facing the country was being able to capture the changes in population. “We do not in this country have draconian administrative ways of recording who is coming in and out,” she said. “That contributes to the statistical challenge for us.”

In London, 28 out of the 33 boroughs suffered a net loss of population as a result of internal migration. The worst was Newham, in East London, which showed a net loss of almost 10,000 residents, followed by Ealing, Brent and Lambeth. London’s official population now stands at 7.5 million.

Ms Dunnell said: “There have been huge changes in business, which impacts on the labour market. London has already been a magnet for people and jobs and always has been a magnet for immigrants because this is where immigrant communities start off.” She said that London was attractive to wealthy incomers who could afford expensive properties, as well as younger migrants willing to live in cheaper rented accommodation. “People want to come to London.”

Sir Andrew Green, chairman of Migrationwatch, said: “It is clear from these figures that immigration is continuing unchecked and continues to break all previous records, despite the fact that this is opposed by the vast majority of the public”.

David Nicholson-Lord, Optimum Population Trust research associate, said: “Out-migration has been climbing for several years and survey evidence strongly suggests it is driven by a perceived decline in quality of life, with congestion, queues, overcrowding and general lack of space a key element in people’s decisions to move.”

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