The head of the Office for National Statistics has stepped down with immediate effect, citing “ongoing health issues”, as the UK data agency comes under fire for flaws in critical economic indicators.
Sir Ian Diamond’s exit comes as a government-commissioned review scrutinises the agency’s leadership, culture and structure after a series of errors in economic indicators, alongside delays to data publication.
The national statistician resigned because health issues meant he was “unable to give the full commitment he would like to drive the organisation forward”, said the UK Statistics Authority, which oversees the ONS.
Diamond has been replaced by Emma Rourke, ONS deputy national statistician for health, population and methods, pending longer-term arrangements, the UKSA added on Friday.
The ONS has been grappling with problems in some of the most market-sensitive data that it produces, making it harder for policymakers to take decisions about how to steer the economy.
The Bank of England has been vocal about the trouble it is encountering setting interest rates given a sharp decline in response rates to the agency’s labour force survey, which underpins critical data such as the unemployment rate.
A “transformed” LFS, intended to give policymakers a more accurate picture, has suffered repeated delays and will now launch only towards the end of 2026.
Diamond, who won praise during his early tenure for the way the agency responded to the needs of the Covid-19 pandemic, said in a statement that it had been “an honour and a privilege to lead the ONS over the past five and a half years”.
But he added that the next phase of delivery for the agency would require “energetic leadership”, including implementing the findings of the independent probe commissioned by the Cabinet Office and UKSA.
“Unfortunately, I have made the decision that, due to ongoing health issues, I am unable to give the commitment to the role of national statistician that I would like to and feel that it is the right time for somebody else to pick up the baton,” Diamond said.
Last autumn, an internal review of the errors that caused the survey’s collapse found failures of leadership had contributed to a crisis in morale at the ONS, with poor strategic choices leading to “systematic and compounding under-investment in surveys”.
An interim review into broader concerns over the quality of figures, published last month by the Office for Statistics Regulation, the regulatory arm of the UKSA, pointed to “insufficient investment” in data collection.
It called on the ONS to take “decisive action to restore confidence”, less than a week after the agency reported a real-terms cut to its budget for 2025-26.
The ONS is now scaling back its work in key policy areas — including the measurement of public sector productivity and of crime against children — in order to focus on its core economic statistics.
Mike Keoghan, another ONS deputy national statistician, left the agency in March.
UKSA chair Sir Robert Chote said Diamond had shown “tireless energy” and overseen many successes at the ONS “during a remarkable period of economic and societal change, particularly during the pandemic”.
Rourke would continue to drive the agency forward “with a renewed focus on high quality economic and population statistics for the public good”, he added.
