The National Audit Office (NAO) has branded the Hinkley Point C nuclear power station as a “risky and expensive project with uncertain strategic and economic benefits”.

The spending watchdog criticised the Department for Business, Energy & Industrial Strategy (BEIS) over the deal it struck with French power giant EDF, which is building the plant.

Amyas Morse, Head of the National Audit Office, said: “The Department has committed electricity consumers and taxpayers to a high cost and risky deal in a changing energy marketplace.

“Time will tell whether the deal represents value for money, but we cannot say the Department has maximised the chances that it will be.”

Costs rising to £30bn

The NAO noted that the expected cost of top-up payments under the Hinkley Point C’s contract for difference has increased from £6 billion to £30 billion.

The watchdog also criticised BEIS for only considering the impact on bills up to 2030, despite the fact that consumers are locked into paying for Hinkley Point C “long afterwards”.

Tom Greatrex, Chief Executive of the Nuclear Industry Association and a former Labour shadow energy minister, said: “While, as with other technologies, follow-on projects will cost less, the NAO analysis of the strike price also highlights that using a different financing structure could have resulted in a lower strike price.”

> Download the NAO's report