Review of energy system operation during extreme heat
- Publication type:
- Transparency document
- Publication date:
- Last updated:
- Topic:
- Electricity transmission,
- National Energy System Operator (NESO)
Allegations on actions and reporting of data by the National Energy System Operator (NESO) between 22 to 26 June 2026.
Claire Coutinho MP has raised concerns about the actions taken and reporting of data by NESO during the extreme heat period.
The main concerns raised were:
- poor record-keeping and whether system risk data was hidden
- improper influence on decision making
NESO has commissioned an independent external investigation. The Terms of Reference in the letter below have been updated. Read the Terms of Reference for the whistleblowing investigation on the NESO website.
We regulate NESO and will make sure that the review is transparent, impartial and has the right terms of reference to get to the facts about what happened.
All updates
3 August 2026 added link to the new Terms of Reference.