Workers at the Total refinery in Dunkirk have voted to continue industrial action, despite management concessions won at a national level on Tuesday.
Most French unions had been expected to call off a strike after crisis talks with Total management.
Europe’s biggest refiner had committed not to close or sell any French refineries for the next five years, except for its Dunkirk plant.
Around 100 employees have voted unanimously to extend the strike, saying they’re not satisfied with the guarantees.
Total supplies half of France with petrol.
The dispute has caused fuel shortages in more than 200 gas stations around the country and sparked panic buying.