A company behind the development of a new nuclear power station is laying off more than half of its workforce.
Japan's Toshiba has been looking to sell off its holding in NuGen to Korea Electric Power Corporation (Kepco).
However, delays in the deal have led NuGen to announce it will reduce its team at the Moorside plant in Cumbria from more than 100 to fewer than 40.
The GMB union said the "looming collapse" of Moorside had been "depressingly predictable".
Justin Bowden, GMB national secretary, urged the government to step in to "eradicate uncertainty".
A spokesman for NuGen said Toshiba had been attempting to sell the firm to Kepco for more than a year.
Due to the "prolonged time" this was taking there would be a "phased reduction in the headcount", he said.
Committed to delivery
The spokesman added: "NuGen's retained core team will be focused on securing a sale of the NuGen business and supporting Toshiba's activities.
"NuGen's aim remains to deliver low-carbon, low-cost nuclear power at Moorside and the company remains committed to delivering this for Cumbria and the UK."
A spokeswoman for the Department of Business, Energy and Industrial Strategy, said the issue was a "commercial decision" for NuGen.
But she added: "Nuclear has an important role to play in the UK's energy future as we continue our transition to a low carbon economy."
NuGen was initially co-owned by Toshiba and the French firm Engie.
But, in April 2017, the Japanese technology giant was forced to buy the 40% of NuGen it did not already own.
It then put the project on hold while it carried out a "strategic review of its options".
In December, it was announced that Kepco was the preferred bidder to take over the project.