The bill, proposed by right-wing MP Paul Salen, was passed in the National Assembly in 2012 and has now made it through a final reading in the Senate.
It allows workers to donate days off anonymously to a colleague who needs to look after a seriously ill child.
Salen based it on the experience of Christophe Germain, an employee at the Badoit water-bottling plant in his constituency, whose bosses agreed that his colleagues could give him their days off when his 11-year-old son, Mathys, was confined to their home with cancer.
Mathys died in December 2011.
Germain attended the Senate’s debate on Wednesday.
The right already existed in some private companies, where local agreements had been made, but is now extended to the public sector.
Some Socialists abstained on the vote, claiming that the law could run into legal problems, while the Communists and their allies voted against on the grounds that it lets employers off the hook of their responsibilities to employees in such a situation.
“Your bill, portrayed as being generous, will completely free employers from their responsibilities and create intolerable situations of injustice between those who can collect days off and those who can’t,” argued left-winger Dominique Watrin.
Labour Minister François Rebsamen expressed “strong reserves” about the measure, pointing out that “rest days are part of the need for the protection of employees’ health” but left it to parliament to decide on the matter.
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