The Financial Times has revealed that significant issues with UK employment data were flagged to the head of the national statistics agency after a key survey’s sample size dwindled to just five individuals. Emails obtained through a Freedom of Information request show that in October 2023, Richard Heys, the deputy chief economist at the Office for National Statistics (ONS), expressed serious concerns about the credibility of the long-standing Labour Force Survey (LFS).

Heys warned that the LFS had “little and falling merit,” highlighting that one industry’s data had shifted by 30% due to the sample size collapse. His concerns were raised in an email ahead of an October 2023 briefing to ONS chief Sir Ian Diamond, which took place just before the agency abruptly withdrew key labour market statistics with only a day’s notice. Diamond later told the Treasury select committee that this briefing was the first time he became aware of the survey’s unreliability, despite its role in shaping vital UK economic indicators like the unemployment rate.

In the same email, Heys referenced a new survey in development—the Transformed Labour Force Survey (TLFS)—which was presenting challenges but was still seen as a necessary replacement for the failing LFS. He argued that the decision to discontinue the LFS should not be delayed until the TLFS was perfect, but rather until it was clearly superior.

Heys also advised ONS officials on how to present the issue to Diamond, cautioning them to sound optimistic but not overly reassuring. He emphasized the importance of acknowledging the seriousness of data quality issues and stakeholder concerns.

The ONS has faced growing criticism from politicians over the reliability of its statistics, with claims that flawed data has created major blind spots for policymakers. The problems with the LFS began during the Covid-19 pandemic when the ONS switched from in-person to telephone interviews, leading to a response rate drop below 15% by late 2023. Despite efforts to transition to the TLFS by March 2024, delays caused by underfunding and excessive optimism have pushed the timeline back to at least 2026.

Internal ONS documents from October 2023 show that stakeholders were hesitant about adopting the TLFS too soon due to concerns over data quality. The ONS declined to comment on the situation.