Britain's top statistics regulator has strongly criticised the Home Office after a “damaging” leak of official migration figures to media ahead of their publication.
Head of the UK Statistics Authority Sir David Norgrove wrote that he was “concerned” about the “seriously misleading” disclosure in a letter sent today to Amber Rudd, the home secretary.
Norgrove said: “Whoever spoke to the journalist seems only to have half understood the data, or inadequately communicated them. The result was seriously misleading, creating confusion where clarity was important.”
Around 50 people, aside from the analysts working on the data, have access to the statistics before publication. The Home Office said it will investigate who leaked the statistics to the Daily Telegraph. The statistics revealed the numbers of overseas student who stay on illegally in this country was far smaller than previously thought.
"The leak was the more damaging in view of the sensitivity of migration data," Norgrove added.
The leaking of official statistics has come under the spotlight in recent months after the UK’s Office for National Statistics (ONS) in June announced it will no longer give ministers early access.
The ONS decision came after statisticians raised suspicions that market-moving figures were being leaked ahead of time, allowing unscrupulous traders to profit from their inside knowledge.
The letter from Norgrove will add to pressure for the government to abolish the early release of statistics. Chris Skidmore, the minister for the constitution, is leading an review of early release by government departments, following on from the ONS decision.
Hetan Shah, executive director of the Royal Statistical Society, said: “This incident from the Home Office shows that the more you have pre-release access to statistics, the more likely those numbers will be leaked.”
“The ONS has set a good example in ending the practice of people having early access to the numbers, and it is now time that the rest of government followed its lead, starting with the Home Office.”
A Home Office spokesperson said the department followed official rules on the pre-release of data “to the letter”.
The spokesperson added: “We have already submitted a report to the Office for National Statistics and we are committed to investigate this matter working with the UK Statistics Authority. It would be inappropriate to comment further.”