By Caroline Wyatt
BBC News, Paris
The French government is proposing plans to ease the rules on the country's 35-hour working week.
Those who are in favour of changes, like truck drivers, are a minority
However, a recent poll shows that the majority of French workers do not want to work longer hours.
The French parliament was due to begin on Tuesday afternoon a three-day debate on a bill that would relax the rules.
The reform would allow workers to put in more than 35 hours a week in return for more pay if they reach a collective accord with their company and union.
The government says this reform is aimed at stimulating the economy and creating jobs.
French workers have been demonstrating over the past weeks in protest against the government's plans.
A recent poll showed that three-quarters of the French workforce want to stick to the current 35-hour working week, brought in by the last Socialist government.
Only 18% say they want to work longer hours. But French Prime Minister Jean-Pierre Raffarin says action is vital to keep the French economy competitive and to create more jobs.
Some companies here say the limits on overtime and the working week are making them uncompetitive, even though French employees are more productive per hour than their American or British counterparts.
French trade unions fear that the bill being debated in parliament is the first step towards abolishing the 35-hour week and they are threatening bigger demonstrations this Saturday.
But the government insists that all it wants is to offer companies and workers more flexibility, allowing those who want to work more and earn more to do so.
Yet the real problem facing France is unemployment, running at almost 10% of the workforce. The Socialists theory that shorter hours would create millions of new jobs did not live up to its promise.
Some employers in France complain that high costs and rigid rules on hiring and firing staff still make them reluctant to employ new workers and that some change is vital if France's economy is to remain competitive.