Ambition, realism and emerging tech: Darren Tierney on tough year for ONS and hopes for 2026

The Office for National Statistics perm sec also picks his choice to turn on the Christmas lights
Photo: Andrew Aitchison/Alamy

By CSW

23 Dec 2025

What was your highlight of 2025?

My standout moment for this year is joining the Office for National Statistics as the new permanent secretary. As a policy professional I have always been an avid consumer of ONS products, so stepping into this role feels like a real privilege. It’s a really exciting opportunity to help shape how we deliver trusted data that underpins policy and public understanding for years to come.

What was the hardest part of being a leader in 2025?

The pace of technological change has been both exciting but challenging. With so many innovations emerging – particularly in AI and automation – the real test has been figuring out how to harness these tools effectively. Somewhere like the ONS – where our business is data – it’s not just about adopting new technology, we need to ensure that it adds genuine value, aligns with what we’re trying to achieve, and remains practical for the department. Balancing ambition with realism with emerging tech is a big leadership challenge.

What are the main challenges facing your department in the coming year? 

2025 has been a tough year for ONS and all who care about the quality of statistics. But we end this year with clear recovery plans in place, some really promising proof points that the recovery is underway, and with a renewed sense of purpose in ONS. I’m determined to keep momentum on our Economic Statistics and Surveys recovery plans in 2026 – and to make 2026 the year of recovery for ONS. Delivering high-quality, trustworthy data on the issues that matter most remains at the heart of what we do, and our recovery plans are vital for that. The brilliant people at ONS will be at the heart of that recovery and I am really looking forward to working with them all throughout next year.

Which celebrity or historical figure would you choose to turn on the Christmas lights in your town – and why?

1970s Elvis. You can’t beat the king…

Read all the entries to this year's perm secs round up here

Categories

Leadership Statistics
Share this page