"I confirm to you today that the state intends to control 100 per cent of EDF's capital", Borne said in her policy speech in the lower house of parliament as she set out her minority's government priorities.

EDF, in which the state already owns 84 per cent, faces delays and budget over-runs on new nuclear plants in France and the United Kingdom as well as corrosion problems in some of its ageing reactors.

Half of its reactors in France are currently offline.

EDF has also been hurt by government rules forcing it to sell power to rivals at a discount while prices hit record highs.

The company has estimated that output losses will reduce profits by 18.5 billion euros ($A27.6 billion) and the discounted power sales will cost it 10.2 billion euros.

Its debt is expected to rise 40 per cent this year to more than 61 billion euros.

The option of fully nationalising EDF was flagged by President Emmanuel Macron earlier this year as he intends to make the company the main pillar of a massive investment in new nuclear reactors.

Borne did not specify if the nationalisation would be carried out via special legislation or through a buyout of minority shareholders, nor did she provide a time frame.

Shares in the group, which were down 5 per cent before the announcement, rose as much as 9 per cent just after it.

Australian Associated Press