Diamond has led the Office for National Statistics (ONS) and Government Statistical Service (GSS) since joining the UK Statistics Authority in 2019, and during that time led the development of the Coronavirus Infection Survey during the pandemic. 

The UK Statistics Authority said that due to “ongoing health issues”, Sir Ian decided he is “unable to give the full commitment he would like to drive the organisation forward”.

Sir Ian’s departure is with immediate effect. Emma Rourke, deputy national statistician for health, population and methods, will act in his place on an interim basis, pending longer term arrangements.

Sir Ian’s resignation follows criticism of the ONS over flaws in its economic data, centred on issues with the Labour Force Survey. Statistics regulator the Office for Statistics Regulation (OSR) is conducting an ongoing systemic review of economic statistics produced by the ONS.  

In April, the government announced a rapid review of the ONS’s delivery of core statistics, its organisational culture, structure and leadership and its relationships with the Cabinet Office and HM Treasury. The House of Commons Public Administration and Constitutional Affairs Committee also opened a separate inquiry into the work of the Statistics Authority.

Sir Ian said: “It has been an honour and a privilege to lead the ONS over the past five and a half years and I have been immensely proud of the prominent role that independent statistics and data have played in informing the critical decisions of the day.”

“The next phase of delivery for the ONS will continue to require energetic leadership, including overseeing the implementation of the Devereux Review findings. 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.”

UK Statistics Authority chair Sir Robert Chote said: “I thank Sir Ian for the tireless energy and passionate dedication he has brought to the role of national statistician and to championing the vital role of statistics across society more broadly.

“He has overseen many successes over his tenure during a remarkable period of economic and societal change, particularly during the pandemic.

“Emma Rourke will be acting up in his place and I know she will continue to drive forward the ONS with a renewed focus on high quality economic and population statistics for the public good as set out last month in the 2025/26 ONS Strategic Business Plan.”

In early April, the OSR published an interim report to help ONS ‘address the stakeholder concerns and the risk of a growing loss of confidence’, according to a letter from OSR director general Ed Humpherson to Sir Ian Diamond.  

The report said the ONS should publish a plan to ‘recover’ its social social survey operation and ‘reduce risk’ in its business survey operation.

Humpherson also said in the letter that the ONS needed to: develop ‘a clearer strategic articulation of the purpose and priorities for economic statistics’; regularly publish a strategy for the data sources used to compile economic statistics; as well as taking ‘a more strategic and systematic approach to quality reviews of its data sources’.