The Government has set a cap on how much it will pay for electricity generated by new nuclear power stations in its negotiations with EDF.
Despite clashes between EDF boss Vincent de Rivaz and MPs on the Environment Select Committee last week over his nuclear plans, it is understood that ministers and the French group are close to agreeing the crucial "strike price". But a final deal is not expected until February.
The strike price gives a guarantee to EDF, which is to build a new plant at Hinkley Point in Somerset, on the lowest payment the company will receive for its nuclear-generated power. Should the market price fall below this, EDF would be paid the difference. This ensures that EDF and other groups leading the nuclear roll-out have a guaranteed return on any investment.