Hitachi had called on the British government to boost financial support for the project.

"Any deal needs to deliver for UK consumers and taxpayer. Despite extensive negotiation and hard work by all sides, the government and Hitachi have been unable to reach agreement to proceed at this stage. The government is committed to the nuclear sector," the spokesman said.

(Reporting by William James, Writing by Kylie MacLellan; editing by Guy Faulconbridge)