£175m subsidy for back-up diesel power prompts calls for investigation

Critics say energy auction rewards carbon emitters as National Grid confirms it has secured 45GW of generation to keep lights on at peak periods

The government is facing calls for an urgent investigation into how companies were awarded more than 175m in subsidies to build heavily polluting "diesel farms" to provide the UK with backup energy generating capacity.

Critics said an energy generation auction overseen by the National Grid had descended into a farce by rewarding intensive carbon dioxide (CO₂) emitters, just as ministers committed Britain to lower carbon emissions at UN climate change talks in Paris.