The Government is being urged to step in and guarantee funding for a new nuclear power station after Japanese giant Toshiba said it was reviewing its investment in overseas nuclear projects.
The GMB union said ministers should take urgent action to secure the development at Moorside in Cumbria.
The future of the planned £10 billion power plant has been thrown into doubt after Toshiba said it was reviewing its overseas nuclear business.
Toshiba owns Westinghouse, the American-based nuclear developer whose AP1000 nuclear reactors are set to be used at Moorside.
GMB national officer Justin Bowden said: " It looks increasingly like bad business investments may have busted Toshiba's role in a new nuclear facility at Moorside in Cumbria.
"The time is now right for the UK Government to step up to the plate and fill any funding gaps to ensure this vital piece of infrastructure remains on track.
"Britain desperately needs the security of supply that nuclear brings if we are to keep the lights on and the economy running over the coming years.
"Relying on foreign money to build our infrastructure is always fraught with risks.
"The sensible thing is for the Government to step in and guarantee the funding, this will keep Moorside on track and push down the price we will all have to pay for the electricity it will produce."