David Cameron has been accused of a “migration cover-up” after it emerged that more than a million migrants who have come to the UK in recent years are unaccounted for.
Ministers have failed to release data which experts believe could show the true number of EU migrants coming to the UK, claiming that it would be “unhelpful” to Mr Cameron’s current renegotiation with Brussels ahead of the in-out referendum.
There were accusations that the figures are being suppressed amid fears that releasing the data could lead to Britain leaving the EU.
Experts warned that it could mean the number of migrants coming to Britain from the EU is actually hundreds of thousands higher than previously thought.
It came as Mr Cameron was left isolated as more than a dozen European leaders spoke out ahead of a crucial Brussels summit to say that they would oppose oppose his plans to strip EU workers of in-work benefits for four years.
Poland, Hungary, Slovakia and the Czech Republic issued a joint statement ahead of the debate, saying that they “will not support any solutions which would be discriminatory or limit free movement”.
Angela Merkel, the German Chancellor, said that while she wants Britain to remain in the European Union there must be no restrictions on “basic freedoms”, while François Hollande, the French President, warned that the proposals are “not acceptable”.
The leaders of Belgium, Italy, Portugal and Luxembourg raised concerns, as did Donald Tusk, the President of the European Council and Jean Claude-Juncker, the President of the European Commission.
Mr Cameron warned them that they will undermine support for Britain’s membership of the EU if they refuse to address concerns over migration.
However, officials suggested he was open to discussing “differing ideas” amid speculation that he will ensure the plans do not discriminate against migrants by applying them to young British workers as well.
The Prime Minister in 2010 pledged that he would get net migration down to the “tens of thousands” by the 2015 election.
However, in recent years the number of foreigners entering the UK has soared.
Official data from the Office of National Statistics shows that around 760,000 EU migrants have settled in the UK in the last four years.
Those figures come from the International Passenger Survey which sees face-to-face interviews with people flying into Britain. Another survey of Britain’s Labour force suggests a slightly lower figure of around 525,000.
However, a recent spike in the number of EU migrants being given National Insurance numbers has seen experts raise questions of the accuracy of that data.
A total of almost two million EU migrants have been allocated national insurance numbers in the last four years – far higher than the 760,000 counted into Britain via surveys.
Although a significant number of those people may have left the country, the Government was asked in a Freedom of Information request to release data it has on how many of those two million National Insurance numbers are “active”, in order to give a much more accurate picture of how many migrants are currently living in the UK.
In a response to the request by Jonathan Portes, an economist, HMRC said that disclosing the data would undermine Mr Cameron’s current renegotiation with Brussels.
HMRC said: “The information is being used to inform the development of policy options as part of the negotiation process and therefore relates to the formulation of Government policy. HMRC continues to believe that releasing information in the form requested would, at this stage, be unhelpful to the negotiation process.”
It is conceivable that the difference in numbers is relatively small. However, critics accused the Government of attempting to “keep the public in the dark” about the true scale of EU migration.
Steve Baker, the founder of Conservatives for Britain, said: “The government runs the risk of being seen to cover up the true scale of EU migration.”
He added: “The government may have worked out they will lose the referendum if this data is released. They know if people realise the true scale EU migration they will to vote to leave.”
Matthew Elliot, the chief executive of the Vote Leave campaign, said: “It’s predictable but depressing that the Government is covering up immigration statistics to keep the public in the dark when they vote.”
Asked how many EU migrants may have been left off the official statistics, Alp Mehmet of the Migration Watch think-tank, said: “It is certainly tens of thousands and could be hundreds of thousands.”
Meanwhile, an official report also found that thousands of asylum seekers have dropped off the Government’s radar.
Caseworkers told inspectors there were around 10,000 cases where the main applicant and any dependants, such as children, were not in contact with the Home Office or had absconded.
Mr Cameron said: “The levels of migration we have seen in a relatively short period of time are unprecedented, including the pressures this places on communities and public services.
“This is a major concern of the British people that is undermining support for the European Union. We need an effective answer to this problem.”
HMRC was forced into a climbdown and late on Thursday insisted that it was “wrong” to suggest the information was withheld because of the EU renegotiation.
A spokesman said: “It was wrong to suggest information was withheld because of the EU renegotiation.
“Not all the information that has been requested is held by HMRC. The information that is held is not in a collated, publishable form. “HMRC will release that data when it is properly collated early in the New Year.”