The UK government says it will make available an additional GBP1.3 billion ($1.9 billion) in funding for the construction of the Sizewell C nuclear reactor project with French energy group EDF.
The announcement from the Department for Energy Security and Net Zero late on Monday takes the level of state funding for the project in eastern England to more than GBP2.5 billion.
Opponents of the project criticised the additional government funding for a development they said lacked transparency and whose main beneficiary would be heavily indebted, French state-controlled EDF.
Energy security has become a more pressing issue for the UK since Russia's invasion of Ukraine in February 2022, and as the country looks to reach net-zero carbon emissions by 2050.
It wants to increase nuclear's share of the energy mix, as it does not emit carbon dioxide into the atmosphere.
Its use as an alternative to fossil fuels is highly controversial, however, with many environmental groups warning about safety risks and the disposal of nuclear waste.
The government gave the green light in July 2022 to Sizewell C and announced in November the same year that it would take a 50-percent share in the project after the departure of original partner CGN of China.
The new money "will allow early construction works to continue ahead of a final investment decision later this year", the department added.
Nuclear minister Andrew Bowie told the Financial Times in an interview published earlier this month that the UK was on track to conclude fundraising for Sizewell C before the end of the year.
The business daily said the government has to raise some GBP20 billion from outside investors.
Earlier this month, the UK government announced plans to build another nuclear power station in addition to Sizewell C and Hinkley Point C, which is under construction in southwest England.
Together Against Sizewell C (TASC), which opposes the development, criticised the additional government funding into what it called a "white elephant".
TASC deputy chairman Pete Wilkinson called it "nothing short of a contemptuous slap in the face for the UK's cash-starved public services".
"Sizewell C remains a purely speculative project, lacking transparency on cost and value for money leaving bankrupt EDF the only winners, laughing all the way to the bank," he said.
