Last night, it was revealed that the number of foreign workers entering the UK over the past 10 years could be 1.5 million, 400,000 more than government figures. The official figure of 1.1 million is also a revised statistic after the Home Office was forced to admit that the government had miscalculated the number of foreign workers entering the UK.
The home secretary, Jacqui Smith, confessed yesterday that it was "bad" that the government had underestimated the net increase in foreign workers over the past decade by 300,000.
But the confusion over how many foreign workers were in the country deepened when the Conservative party unearthed statistics claiming the figure was 1.5 million.
The Tories dug out a parliamentary answer from July when the national statistician, Karen Dunnell, said, "For the three-month period ending March 2007, there were 1.5 million overseas-born people in employment who had entered the UK in the last 10 years."
Chris Grayling, the shadow pensions secretary, said, "This situation just gets worse; it's clear we simply can't trust the figures or statements put out by the government on migrant workers in the UK."
However, a spokesman for the Department for Work and Pensions said the additional 400,000 were largely made up of the children of returning British ex-pats.
"The parliamentary answer relates to workers born overseas and there are 1.1 million foreign nationals working in the UK.
"The remaining 400,000 are people who were born overseas but are UK citizens; they are not foreign nationals," he said.
The department's bid to shore up the credibility of immigration statistics was further undermined after Richard Alldritt, head of the official watchdog on statistics, told the Guardian that ministers had been under pressure for years to spend more money on producing reliable figures.
Mr Alldritt, said he had been campaigning for more than four years to persuade ministers to spend "tens of millions" to increase the accuracy of work on entries, exits and movements within the UK.
This morning, the prime minister outlined plans to restrict the number of people from outside the EU seeking work in Britain. These include an Australian-style points system, ID cards for foreign nationals and keeping a count of how many people enter and leave the country.
"Over the next few months, we have decided on changes that will make the system work in such a way that people can be sure that we are taking the action that is necessary and, of course, at the same time benefiting where we want to from the skills that people can bring to our country," he said during an interview with GMTV.
Mr Brown added that there were 600,000 job vacancies in the economy and he was "really keen" to get British people to take up these vacancies.
Liberal Democrat leadership challenger Nick Clegg, the party's home affairs spokesman, said the confusion showed immigration figures should be taken out of the hands of the home office.
"This statistical spat between the government and the Tories will leave many people completely confused and damage public confidence in the immigration system even further.
"That is why the Liberal Democrats have long called for all immigration statistics to be made the responsibility of the Office of National Statistics, which should also be given more resources and independence to do its job properly," he said.
