Atlantic (SSE), Bristol Energy, British Gas, Co-operative Energy, Economy Energy, EDF, E.on, Extra Energy, First
Utility, Fischer Energy, Flow Energy, GB Energy, Manweb (Scottish Power), M&S Energy (SSE), Npower, Our Power,
Ovo Energy, Sainsbury's Energy, Scottish Gas (British Gas), Scottish Hydro (SSE), Scottish Power, Southern Electric (SSE), Spark Energy, SSE, SWALEC (SSE), Utilita,
Utility Warehouse.
The summit, including smaller firms like First
Utility,
OVO Energy, Good Energy and Utilita will see the Energy Secretary along with the chief executive of industry regulator Ofgem, Alistair Buchanan, explore ways the marketplace could be made fairer to increase competition.