The factory, made possible by government subsidies, could produce nearly half of the electric-car batteries needed in Britain by 2030.
Stellantis said post-Brexit export rules and the lack of a domestic battery manufacturer could force it to close its plants in Britain.
The failure of Britishvolt is a blow to Britain’s plans to promote the manufacture of electric cars, and threatens the future of its automotive industry.
The Japanese carmaker will also manufacture a new electric vehicle in England as part of a £1 billion investment, partially supported by the government.
Lacking a strong domestic battery industry, Britain may be left behind by the shift to electric cars.
Goals include ending sales of gas and diesel cars by 2030, achieving net zero carbon emissions by 2050 and, perhaps, pleasing a new sensibility in Washington.