French strikers blockading oil refineries have forced 1,600 petrol stations to close across the country, leading to a rush to open pumps by panicked drivers.
Six of France's eight refineries are currently closed as a result of industrial action, with activists holding protests outside.
Prime Minister Manuel Valls said the government would do what it could to end the blockades, moving the strikers if necessary.
"We are determined there will be no shortages in France," BFM TV reported him as saying, during a visit to Israel.
"We will continue to clear a number of sites, including the depots".
Le Point reported that out of France's 12,000 service stations, 816 are completely out of fuel and a further 800 did not have one type of fuel.
Transport Secretary Alain Vidal told Europe 1 radio that in the worst affected towns and cities, just 60% of the service stations are open.
The blockades are the latest action in months of protests against proposed changes to France's labour laws, which would make it easier for employers to hire and fire workers.
The government pushed through a new bill on May 10th without having a vote in parliament.
Dozens of protesters arrested
Last week, riot police fired tear gas and water cannon at protesters as dozens of people were arrested.
Up to 1,000 people have been detained since the start of the demonstrations, with the total number of officers hurt said to be about 350.
Lorry drivers have been blocking major roads and strategic junctions, notably in the Bordeaux region, where they have turned away deliveries to supermarkets and fuel supply hubs.
The main action is being organised by the CGT union (General Confederation of Labour).
Departmental secretary of the CGT Maxime Picard, who was one of those taking part in a 500-strong blockade of a fuel depot at Fos-sur-Mer, west of Marseille, told Le Point: "We want the withdrawal of the Labour Law".
President Francois Holland was determined to push through the legislation because he believes liberalising the labour market is the only way to tackle France's unemployment problem.
The new laws allow some employees to work far longer than the 35-hour week set down in previous legislation and make it easier to fire workers when companies run into economic difficulties.
The row over the reforms has plunged Mr Hollande's administration into crisis, forcing it to win a 'no confidence' vote.
The confidence vote came after Mr Valls invoked a rarely used clause in France's constitution, which allows reform by decree, to push through the bill which updates France's existing 3,000-page Code de Travail (Employment Rules), which has been described as "bloated" and "unreadable".
