Data could show more EU migration before vote

HM Revenue and Customs said it will provide statistics on how many National Insurance numbers are actively being used by EU citizens.

The figures will be given to the Office for National Statistics to publish in May, just weeks ahead of the EU referendum.

Current figures about the number of EU citizens living in the UK are based on the number of people entering the country but concerns about the quality of the data was raised last month by the statistics watchdog. The UK Statistics Authority warned that discrepancies between the sets of figures could undermine public confidence.

Head of the watchdog Ed Humpherson said figures for National Insurance numbers issued to foreign nationals are traditionally higher than the ONS’s international migration estimates.

Conservative MP Andrew Tyrie, chair of the Treasury Committee, urged HMRC back in December to publish the number of European citizens who had registered for a National Insurance number.

HMRC chief executive Dame Lin Homer confirmed in a letter to the MP that the figures would be provided to the ONS for publication.

Mr Tyrie said the commitment from HMRC had been obtained as a result of a “good deal of persistence”.

“Since receiving it, I have pressed further, receiving an assurance that it should be possible to supply the information to the committee before the end of this month,” he said.

“Late, but a good deal better than never.”

Migration has been one of the most divisive issues of the EU referendum campaign and the figures are likely to be seized upon by Leave campaigners if they prove to be higher than current official statistics.