ONS report disproves 'beyond doubt' claims of an EU immigration cover-up

There is no such thing as a cover-up over EU immigration figures, a major report has found, with a large gap between two official figures accounted for by migrant workers who only come to Britain for short periods.

Those campaigning for the UK to leave the EU had used the gap in statistics to claim immigration had been vastly underestimated, pointing at figures for new National Insurance number registrants that were much higher than official estimates.

But in a much-awaited report, the Office for National Statistics concluded that the difference was down to “short-term migrants”, who come to the UK for a period of employment, study or work between one and 12 months.

The new report is significant because it comes just six weeks before Britain’s referendum on its EU membership, and immigration represents one of the top two concerns for those considering voting to leave.

In February, The Sun was among a number of papers which accused the government of “conning” the public with figures saying 257,000 people came to the UK from the EU in the past year.

The economist Jonathan Portes had obtained figures to suggest 655,000 EU migrants registered for a new National Insurance number to be allowed to work in 2015, and marvelled at the discrepancy.

But the ONS now says the difference comes down to the fact that official estimates, based on surveys of people arriving at ports, airports and through the Channel Tunnel, only considered arrivals who intended to stay in the country for a year or more.

Thursday’s report concluded this International Passenger Survey, which involves around 800,000 interviews each year, “continues to be the best source of information for measuring long-term international migration”.

It said: “Definitional differences between these data are fundamental and it is not possible to provide an accounting type reconciliation that simply 'adds' and 'subtracts' different elements of the NINo registrations to match the LTIM definitions.

“NINo registrations data are not a good measure of LTIM, but they do provide a valuable source of information to highlight emerging changes in patterns of migration.”

Downing Street welcomed the report, with a spokesman saying the issue raised by Leave campaigners was now “put beyond doubt”.

“Short-term migrants have never been included in the long-term migration statistics, which are governed by UN definitions,” he said. “It would be completely wrong for anyone to try to distort or misrepresent these figures any further following the independent ONS's conclusions.”