Sir David Norgrove, chair of the UK Statistics Authority, has urged the home secretary Amber Rudd to review the practice of allowing officials pre-release access to official statistics produced by the department following a leaked report on international students overstaying their visas.
In a letter to Rudd, Norgrove said he was concerned over the early disclosure of the report, which claimed that 97% of non-EU students leave Britain after their studies and that there are tens of thousands fewer immigrants in the country than previously thought.
Excluding Home Office analysts who complied the data, 50 people were given access to the figures ahead of their official publication date, and information was leaked to the Daily Telegraph.
He highlighted that the Office for National Statistics stopped allowing ministers an early look at its official data in July, and Norgrove is now calling for the Home Office to follow suit for its own publications.
The Home Office data found that the number of students overstaying their visa was only around 4,600, much less than previously thought, leading the government to commission a review of the impact of student migration.
Norgrove, a former Treasury economist, branded the leak “seriously misleading”, and particularly “damaging in view of the sensitivity of migration data”.
Speaking to Civil Service World in June, Norgrove said the use of data was more important in light of the UK’s decision to leave the European Union, which threw up migration as “a central focus over the next five years”.
In his letter to Rudd, he wrote: “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.
“But a more accurate leak would still have been misleading, because it would have been partial (in all senses), and left the journalist and the public lacking context.”
Home Office statisticians are now preparing a report on the breach of the statutory Code of Practice for Official Statistics, he added.
A Home Office spokesman said: “The government has clear rules around pre-release access to official statistics and the Home Office followed these to the letter.
“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.”
The letter was also copied to cabinet secretary Sir Jeremy Heywood and Chris Skidmore, the minister for the constitution, who is leading a review of pre-release access.