- Whistleblowers have alleged that the UK electricity grid fell outside safe operating limits during a heatwave in June 2025, leading to a potential cover-up by senior officials at the National Energy System Operator (Neso).
- In July 2025, Neso commissioned Eversheds Sutherland to conduct an investigation into the allegations, but concerns have been raised about the inquiry's independence due to staff being required to report through the head of legal.
- Claire Coutinho, the shadow energy secretary, has criticized the inquiry as a 'sham' and highlighted a 'cover-up culture' within Neso, questioning the independence of the investigation.
- In May 2025, the Tories raised concerns about grid security, which were dismissed by Ed Miliband as scaremongering.
- On June 23, 2025, a heatwave caused tight margins in electricity supply, leading the grid to cut power exports and issue rare electricity margin notices.
The UK energy grid is facing serious allegations of operational failures during a recent heatwave, with whistleblowers claiming that the National Energy System Operator (Neso) breached safety standards.12
Claire Coutinho, the shadow energy secretary, revealed in Parliament that Neso staff reported the grid fell outside safe operating limits on June 23, during a period of extreme heat exceeding 34C.56
Whistleblowers allege that corporate affairs staff pressured control room engineers to avoid necessary actions, raising concerns about a potential cover-up culture within Neso.
Coutinho stated, “How can this be an independent inquiry if senior managers within Neso are setting the terms?” She emphasized the gravity of the situation, warning that “life and death” decisions are made daily, and failure to manage the grid could lead to blackouts.
The investigation into these claims has been criticized for lacking independence, as Neso is reportedly monitoring staff participation.
Neso has acknowledged the challenges faced during the heatwave, stating that they cut power exports to maintain grid stability, but insisted that the system operated securely without disconnecting customer demand.
The situation has prompted calls for emergency measures to prevent rolling power cuts, with critics arguing that the current management is failing to address the pressing issues.
As the investigation unfolds, the implications for the UK's energy security remain significant, with fears that the grid's fragility could lead to dire consequences in the future.
“Whistleblowers claimed corporate affairs staff were inappropriately involved in operational decisions during the June 23 heatwave, and staff must identify themselves to Neso's head of legal before providing information to the investigation. Shadow energy secretary Claire Coutinho said the inquiry risks becoming 'a sham' and that there is a 'cover-up culture within Neso'.”
GB News
The Times
