The chief financial officer of EDF Energy has resigned ahead of the French energy giant's plans to build the first new nuclear power plant in the UK in decades.
Thomas Piquemal reportedly quit because of concerns that a final decision on investment for a new reactor at Hinkley Point will be made too soon, potentially threatening EDF's financial position.
The company, which is 85% owned by the French government, recently gave assurances that it was close to making a decision on the proposed £18 billion Hinkley Point C project in Somerset.
The company said Mr Piquemal will be replaced by Xavier Girre, who joined EDF last year as chief finance officer for France.
Labour has urged the UK Government to draw up a plan B in case EDF scraps the project.
Shadow energy secretary Lisa Nandy said on Friday that the future of nuclear energy in Britain "cannot just be about Hinkley Point C".
She said the project had been "hit by one delay after another" and highlighted the lack of a final investment decision.
"Given the power crunch we face, it is increasingly clear ministers need a plan B in case it is never built," Ms Nandy said.
After a summit in France last month, Prime Minister David Cameron and French president Francois Hollande issued a communique that said there had been "major progress" in recent months "with a view to confirming the project".
EDF also said it will extend the life of four of its UK nuclear power stations by between five and seven years.