The strike is expected to cause further disruptions the transport network which is already suffering from a shortage of fuel. Further transport disruption is likely later in the week as Paris metro staff are due to begin indefinite action on Thursday and Air France pilots have voted to strike over pay.
French president Francois Hollande has insisted he will not back down over the reforms, which aim to make it easier to recruit and dismiss employees.
On Monday, six of France’s eight oil refineries were still halted or running at reduced capacity due to union action.
The General Confederation of Labour (CGT) union is leading the action, supported by other unions including Force Ouvriere and Unef, whereas the more moderate CFDT union backs the labour reforms.
The CGT says the reforms will erode job security without bringing down the country’s 10% unemployment rate.
Clashes between protesters and police were seen at last week’s rallies saw and the Paris tourist board warned that the scenes of violence risked putting off visitors.
Nevertheless, 46% of French people remained supportive of the protests despite the disruption to their daily lives, according to a poll in the French newspaper Journal du Dimanche on Sunday.