Footage has been released of cracks found inside a reactor at a nuclear plant in Scotland.
EDF has reported a sharp drop in UK earnings last year as it lost 200,000 customers to rivals amid a “highly competitive” market.
More than a million energy customers on EDF’s standard variable tariff face a 10% price increase from April 1.
The energy regulator has increased its price cap on variable tariffs due to rising wholesale prices.
EDF Energy is to increase its standard variable electricity tariff by 1.4% – £16 a year – from June, affecting around 1.3 million customers.