Europe's top human rights watchdog is to rebuke France for its failure to explicitly ban smacking children, Le Monde newspaper reports.
French law forbids violence against children, but recognises the parents' "right to discipline" children.
The Council of Europe will say that the laws on corporal punishment are "not sufficiently clear, binding and specific", Le Monde says.
The council did not comment. It is to issue its formal ruling on Wednesday.
It follows a complaint by British children's charity Approach, which argues that France and other council members are violating a section of the European Social Charter calling on signatories to protect children.
The council has called for all of its 47 members to ban corporal punishment of children. So far, 27 have banned the practice.
The laws in France have occasionally caused controversy.
In 2013, a father was fined €500 ($560; £364) for spanking his nine-year-old son, a case that reignited the debate about corporal punishment in France.
The Council of Europe is due to announce its decisions on other countries included in the Approach complaint in May.