This Practice Note explains when, and to what extent, bodies in the GB energy sector may be amenable to public law challenge, namely through judicial review. It also provides links to past examples of judicial review against key organisations in the GB energy sector, including judicial reviews against Ofgem and energy-related judicial reviews against the Secretary of State for Business, Energy and Industrial Strategy/Energy and Climate Change (BEIS/DECC), the predecessor departments to the Department for Energy Security and Net Zero (DESNZ).