Britain’s grid operator has been accused of concealing system failures that critics claim could increase the risk of blackouts.
Claire Coutinho, the shadow energy secretary, has alleged that senior managers at the National Energy Systems Operator instructed control-room staff to avoid keeping permanent records of operational decisions during periods of grid stress.
Neso is responsible for balancing electricity supply and demand across the UK and maintaining system stability. It was separated from National Grid after Ed Miliband became energy secretary in 2024.
Coutinho has written to the Information Commissioner’s Office requesting an investigation into the claims, which she said were raised by a whistleblower inside the organisation.
According to Coutinho, staff were allegedly told to use live documents with no version history, creating no permanent audit trail of key decisions. She claimed this was intended to prevent full records being preserved for potential Freedom of Information requests.
The allegations relate to periods of system pressure, including late June, when the grid’s frequency reportedly became unstable and dropped below Neso’s operating limit.
Grid frequency must be kept close to 50 hertz, with only limited variation allowed. Significant deviations can cause parts of the electricity network to trip out, raising the risk of supply disruption.
Coutinho also alleged that members of Neso’s corporate affairs team interfered in control-room decisions in an attempt to protect the organisation’s reputation.
She described the claims as “nothing short of a scandal” if proven true.
Energy minister Michael Shanks rejected suggestions that the grid had been insecure, accusing the Conservatives of “scaremongering”. He said the UK power system had remained resilient during the recent heatwave and that consumer demand had been met at all times.
However, Shanks acknowledged the seriousness of the allegations and said Coutinho should share any supporting information with the department.
Neso has recently faced scrutiny after issuing electricity margin notices during June’s record-breaking heatwave. These notices ask power plant operators to increase generation to help maintain system balance. Neso said at the time that electricity supplies were not at risk.
The controversy comes amid wider debate over the UK’s changing energy system, as the growing share of wind and solar power creates new challenges for balancing supply and demand.
Neso and the Department for Energy Security and Net Zero were contacted for comment.
