An EDF board member has resigned ahead of a vote in which the Hinkley Point nuclear plant is expected to be approved.
Gerard Magnin, one of 18 board members, said the project is financially "risky" and will steer France further away from renewable energy sources.
In a resignation letter to chief executive Jean-Bernard Levy, seen by Reuters, Magnin said he was disappointed EDF's strategy was moving more and more towards nuclear power.
"I no longer want to support a strategy that I do not agree with," Magnin wrote.
Almost immediately after EDF announced it was ready to proceed with Hinkley C, the government announced it wasn't.
French energy company gives final approval to nuclear site, in a move set to anger environmental campaigners but delight unions.