The boss of E.Leclerc has warned that the supermarket chain could reduce the opening hours of its stores as part of emergency measures to deal with the risk of power shortages linked to the war in Ukraine.
"For this winter we have a crisis scenario where Russia cuts gas supplies," Michel-Edouard Leclerc told France Info radio.
Under that scenario, "We could close some stores during certain hours," he said.
Michel-Edouard Leclerc heads Les Centres E. Leclerc, a cooperative association of about 600 retailers that competes against Carrefour and Casino.
Its low-price policy has helped it become France's biggest food retailer by market share.
'Energy Restraint Plan'
French President Emanuel Macron said on 14 July he would soon submit an "energy restraint plan" that would ask all citizens to commit to a general "hunt for waste", such as turning off lights when leaving offices.
France's supermarket sector – acting through the Perifem federation – had agreed earlier this month on energy saving measures that would be implemented from 15 October, Leclerc said.
The measures notably include switching off illuminated signs as soon as a shop closes and systematically reducing light intensity. Lighting of sales areas is to be reduced by half before the public arrives and by 30% during critical consumption periods.
Energy prices, which were already increasing before Russia sent troops into Ukraine at the end of February, have sharply risen since then, leading to the highest inflation in most major global economies in decades.
With about 17% of its supply coming from Russia, France is less dependent on Russian gas than some of its neighbours are.
But concerns about supply from Russia come as France grapples with already limited electricity generation due to unexpected maintenance at ageing nuclear reactors, prompting concern over winter shortages.