The Office for National Statistics (ONS) has admitted that the number of eastern European immigrants who came to Britain in the past decade was hundreds of thousands higher than previously thought.
The admission is likely to add to concerns about the level of immigration from eastern Europe to Britain, which many believe is already too high.
The agency admitted that it had failed to count an estimated 350,000 immigrants who arrived in the UK between 2001 and 2011 due to “inadequate sampling” in a survey at airports. The survey measured the difference between the number of people emigrating from Britain and the number arriving, and is used to estimate net migration.
The Daily Telegraph reports that the ONS said that most of those omitted were from Poland and other eastern European states that joined the EU in 2004. The revised totals have now increased the net migration figures for 2001-2012 from under 2.2 million to over 2.5 million.
The “inadequate sampling” occurred because the ONS focused on Britain’s main, large airports, such as Heathrow, Gatwick and Manchester, but ignored the growing number of migrants arriving on budget flights at smaller airports
It also said that it underestimated the number of children arriving in Britain.
The immigration figures cover most of the previous Labour government’s time in office. The party now admits that it was wrong not to impose restrictions on immigrants arriving from the eastern European countries that joined the EU in 2004.
Carlos Vargas Silva, senior researcher at the Migration Observatory at Oxford University, told the Telegraph: “We have known for some time that net migration must have been much higher during the 2001 to 2011 period than the official estimates had suggested.
“This report provides important evidence of the need for better migration data and of the limitations of using a survey to develop net migration data.”
Sir Andrew Green, chairman of Migration Watch UK, said: “This is final confirmation that net foreign migration under Labour totals nearly four million, two thirds from outside the European Union.
“It also shows that the peak of net migration was nearly 275,000 a year, making it even more difficult for the present Government to get the numbers down to tens of thousands.”