E.D.F. Power sector workers will join rail and public sector workers who will take to the streets on Thursday to protest against President Emmanuel Macron's planned reform of the rail and French civil service.
The CGT said the French power sector was under the threat of planned liberalisation reforms which could jeopardise French energy security.
"On March 22, electricity and gas sector workers will go on strike, and plan to disrupt output at their sites, and will demonstrate in Paris and other places to defend the public service," CGT said in the statement.
The union did not say by how much it planned to curb French power production on Thursday. French state-controlled utility EDF (>> Electricité de France), which operates France's 58 nuclear reactors, was not immediately available to comment.
The strike coincides with a week of cold weather across much of western Europe which has increased power demand for heating.
French electricity grid operator RTE forecast peak electricity demand at 78.2 gigawatts (GW) on Wednesday, and 77 GW on Thursday as temperatures fall by over 3 degrees Celsius below seasonal norm.
France's power grid operator RTE said in a separate statement on its website that workers at Uniper's (>> Uniper SE) French power generation sites plan to strike on Thursday but it was uncertain whether it would have an impact on output.
(Reporting by Bate Felix and Caroline Pailliez, Editing by Dominique Vidalon Louise Heavens)
