French energy giant EDF has been told to hold off committing to the Sizewell C nuclear power station in Suffolk after costs for the project have reportedly doubled.
A report in the Financial Times said the cost of project is now twice the original forecast of £20 billion.
One senior Government source and two industry observers said £40 billion was a reasonable assumption for the cost of building Sizewell C in 2025 prices.
The nuclear plant would generate enough electricity to power around 6 million homes.
A spokesperson for the government subsequently said it did not recognise the £40 billion figure while Sizewell C’s management said the number was speculative and not accurate.
France’s state auditor though has recommended that EDF waits until it has reduced its stake in another UK nuclear power development, Hinkley Point C in Somerset.
La Cour des Comptes, the French auditor, wrote in a report: “La Cour therefore recommends that EDF should not take a final investment decision on Sizewell C before achieving a significant reduction in its financial exposure to Hinkley Point C.”
Hinkley Point C is under construction and like Sizewell C will power six million homes.
EDF has a majority stake in the plant but wants to get other investors involved to reduce its exposure and help offset the soaring costs after repeated delays.