As well as its plants in France, EDF owns the UK’s nuclear fleet and several UK gas-fired power stations, and is building the new Hinkley Point C nuclear power plant in Somerset. 

It also has about 11pc of the UK domestic electricity market and about 9pc of the gas market.

The French government move comes as UK ministers face growing pressure to protect consumers from an expected 56pc increase in average bills to about £2,000 when the energy price cap is reset in April to reflect months of soaring wholesale costs. 

Potential measures put forward by industry and rival political parties include a VAT cut on energy bills, removing environmental levies from bills and a windfall tax on North Sea gas producers that have benefited from the price surge. 

A global shortage of natural gas supplies is at the heart of the crisis, pushing up power prices as much electricity is still produced in gas-fired power plants. 

However, outages at ageing nuclear power plants in both the UK and France have worsened the situation by constraining power supplies. 

EDF on Thursday cut production forecasts due to longer than expected repairs  – a move likely to put further pressure on power prices.