France should reconsider its plan to retire a dozen of EDF’s nuclear power plants by the middle of the next decade, as recent unplanned outages and an expected increase in electricity demand highlight risks to energy security, the country’s nuclear regulator said.

“Within five years, we’ll have to revisit the planned decision to halt 12 reactors by 2035,” Bernard Doroszczuk, the president of France’s nuclear safety authority ASN, told reporters. “We must really weigh this decision, given the power production needs and the need to keep margins in the electricity system in case of unexpected events.”

Mr Doroszczuk’s warning comes as natural gas supply shortages, combined with low availability of EDF’s nuclear plants, adds to supply concerns. High energy costs in France and neighbouring countries have forced governments to intervene with tax cuts and price caps.