A number of Britons driving in France have been stranded after running out of fuel due to shortages caused by an industrial dispute, a breakdown recovery firm said.
The AA revealed that several of its members have needed assistance due to filling stations imposing restrictions amid blockades of fuel depots in protest at labour market reforms.
The Foreign and Commonwealth Office updated its travel advice with a warning over fuel rationing in parts of northern and north-west France.
Edmund King, AA president, said: "AA breakdown services in Europe have been taking calls from UK drivers this morning who have run out of fuel. We are recovering vehicles stuck at the side of the road to places of safety until fuel supplies are resumed."
Petrol and diesel is cheaper in France so many UK drivers often set off with low fuel and plan to fill up after crossing the Channel.
But the AA warned that this strategy could backfire.
Mr King said: "We are strongly advising our members heading to France to fill up their tanks before crossing the Channel and moderate their driving to get the best miles per gallon from their fuel. The only silver lining might be less traffic that will allow a car to travel further, typically 300 miles on one tank of fuel."
The problem could deepen later this week as families travel to France for a half term or bank holiday break.
The Freight Transport Association reported that UK lorry drivers are also struggling with the fuel shortage.
Belfast-based Tony Henderson, who regularly travels to France, said some filling stations are limiting drivers to buying less than a quarter of a tank of petrol.
"If you can't get fuel, you can't move," he said. "And if you have a full tank then you're a sitting target overnight for thieves. It's a Catch-22 situation. It would help if the overhead gantries on the motorways gave information but there's no help at all."