Committee publication · Correspondence · 21 October 2025 · HC 847

Letter from Darren Tierney, Permanent Secretary, Office for National Statistics on further information in relation to the work of the UK Statistics Authority Inquiry, dated 13.10.25

From: Public Administration and Constitutional Affairs Committee

Inquiry: The work of the UK Statistics Authority

Summary

Permanent Secretary Darren Tierney responds to PACAC's request for further information about the UK Statistics Authority's budget, prioritisation, and governance following Sir Ian Diamond's departure. The letter provides details of Treasury correspondence during the 2025 Spending Review process, explains how flat cash funding constraints have driven prioritisation decisions, and outlines recent governance restructuring under new leadership.

Key findings

  • HM Treasury set UKSA's 2025/26 budget at 'flat cash' (nominal 2024/25 level), representing £16m (4.4%) real-terms cut, creating pressure to cut outputs unless departmental funding increases
  • Sir Ian Diamond formally flagged risks of flat cash settlement in September 2024 and subsequent submissions, warning of inability to stabilise surveys, transition to international standards (SNA25), or fully support government missions without additional funding
  • HM Treasury emphasised minimum requirements for quality economic statistics (prices, national accounts, labour market, population data) and required detailed project plans for survey recovery and business cases for major programmes (IDS, FPMS)
  • Since Tierney's arrival in August 2025, ONS has undergone governance restructure: Executive Committee expanded and meets weekly; sub-committees eliminated; new mission statement and leadership commitment developed; planned further review of membership and reinstatement of targeted sub-committees
  • ONS responded to Devereux Review recommendations by publishing an economic statistics plan, triggering further activity review to free resources; new prioritisation exercises conducted with staff engagement forums

Tone

Procedural

Topics

public-financegovernment-statisticsorganisation-governancespending-review

Key actors

Darren Tierney, Sir Ian Diamond, Emma Rourke, Simon Hoare, HM Treasury, UK Statistics Authority, Office for National Statistics, Cabinet Office

Notable line

Maintaining 2024/25 funding in cash terms for 2025/26 will be very difficult for us, as the accompanying evidence note makes clear. It represents £16m (4.4%) in effective real terms cuts to our capacity.

Key Quotes

Maintaining 2024/25 funding in cash terms for 2025/26 will be very difficult for us, as the accompanying evidence note makes clear. It represents £16m (4.4%) in effective real terms cuts to our capacity.
Sir Ian Diamond · On the real-terms impact of the flat cash Spending Review settlement
In light of recent concerns around the quality of some key economic statistics – e.g. the Labour Force Survey – HM Treasury, having consulted with Cabinet Office, have taken the decision to provide greater clarity to UKSA on the minimum economic statistics and standards that are required during this Spending Review period.
HM Treasury (Sam Beckett) · Setting conditions on Treasury priorities for UKSA funding
To secure our core economic and social outputs, we scaled back improvements to the Crime Survey for England and Wales (CSEW) and our responsiveness to new government inquiries through the Opinions and Lifestyle Survey (OPN). We also reduced our climate and environmental activities and broader analytical capabilities to direct resources towards our core statistics.
Sir Ian Diamond · Explaining how prioritisation under budget constraints affected statistical output
Since joining the ONS in August, the Executive Committee (ExCo) and I have been reviewing the entirety of the organisation's activities. I am committed to engaging more closely with colleagues across the ONS to help prioritise, better define organisational purpose and address the necessary changes in culture and ways of working.
Darren Tierney · On his approach to organisational restructuring and staff engagement since arrival
Following discussions at ExCo, and in line with the Code of Practice for Statistics, we will engage with users on our prioritisation plans.
Darren Tierney · On future engagement with statistical users regarding ONS priorities
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Source · parliament.uk record ↗

Letter from Darren Tierney, Permanent Secretary, Office for National Statistics on further information in relation to the work of the UK Statistics Authority Inquiry, dated 13.10.25 | Beyond The Vote | Beyond The Vote