The Department of Energy and Climate Change said it is up to the energy companies to justify their profits.
A departmental spokesman said: "Profits are a matter for energy companies to justify to their customers and shareholders, but profits are needed if they are to continue to invest in Britain's energy security and infrastructure".
More top news
The rail union have slammed the move saying China is set to make "a killing at the British taxpayers' expense".
US-backed rebel fighters say they have taken control of a key airbase near the so-called Islamic State's stronghold of Raqqa.
A primary school has taken action after pupils brought in an variety of "worrying" packed lunches - including a two-day-old McDonalds.