Britain 'facing immigration at rate of 250,000 a year

Immigration to Britain has doubled over the past 10 years, according to a report launched today by the thinktank Migration Watch UK.

The level of immigration will run at nearly 250,000 a year - more than two million a decade - for the foreseeable future, according to the study, an influx said to be the equivalent of adding apopulation the size of Birmingham every five years.

The report, Migration - Its Present and Future Scale, suggests that, based on previous experience, around two-thirds of the newcomers will move to London and the south-east, the most crowded area in the country.

Ministers have acknowledged that Britain is short of workers, particularly in the economic hotspots. The government has adopted a formal policy of encouraging workers from abroad. The nationality, immigration and asylum bill, going through parliament, includes measures to open Britain up to migrants.

Based on long term statistical projections, the government is expecting around 135,000 incomers a year.

The Treasury recently disclosed that immigrants account for about 8% of all employees.

Migration Watch UK describes itself as a independent thinktank, chaired by the former diplomat Sir Andrew Green. Its report warns ministers that current levels of migration may be unsustainable. It estimates that at least 60,000 illegal immigrants are added to the total every year, of which 35,000 entered legally but overstayed their permission, while the other 25,000 entered undetected.

In 2000, the last year for which figures were available 183,000 more people arrived in Britain intending to stay, than left the country as emigrants. The figures were similar in the previous two years. A spokesman for the Home Office said: "We have received this report only recently and we're still studying it.

"We obviously take the issue of illegal immigration very seriously.

"What we're clear on is that economic migrants do play a valuable role in the UK, and have done in the past. What we need to ensure is that there are ways and means for people to do that legally."

Home Office figures published recently show there were more than 90,000 asylum applications last year, with around 40% of the applicants given permission to remain.

Early figures from last year's census are expected to show that the UK population has risen above 60m, and is heading for 65m by 2025. As the indigenous population is producing fewer children than in the past, immigration may well prove to be the main economic motor.

Around one child in eight is now from a minority ethnic background, a figure rising to one in three in London.