The total cost of upcoming nuclear power plant Sizewell C is expected to be double the initial estimates, the Financial Times (FT) has reported.

With the UK’s ageing fleet of eight nuclear power stations in need of replacement, and only Hinkley Point C currently undergoing construction, Sizewell C will play an important role in backing up renewable energy in the switch away from fossil fuels.

EDF, the French state-owned energy firm overseeing the construction of both power plants, gave Sizewell C a budget of £20bn in its 2020 development consent submission, But the FT reports that people close to negotiations now estimate it will cost closer to £40bn in 2025 prices.

The government had already proposed subsidising the construction of the project by £5.5bn as the project struggles to attract additional investment. But according to accounts published at Companies House last week, there has been “good progress” with private investors in recent months.

The Treasury will make a final decision...