A top European rights body was expected to scold France on Wednesday for failing to completely ban the smacking of children, in a ruling likely to reignite debate over the controversial topic.
The Strasbourg-based Council of Europe is expected to rule that French law is not "sufficiently clear, binding and precise" on the matter, according to daily Le Monde.
France bans violence against children but does allow parents the "right to discipline" them.
However, French law does forbid corporal punishment in schools or disciplinary establishments for children.
More than half of the 47 members of the Council of Europe, including Germany, the Netherlands and Spain, have completely banned smacking.
Other big European countries, such as Britain, either have similar laws to France or have not adopted concrete regulations on the issue.
Worldwide, 17 other countries have a complete ban on corporal punishment for children, notably in South America, Central America and Africa.
The Council of Europe is ruling on a complaint lodged by Britain-based child protection charity Approach, which says that French law violates part of the European Social Charter, a treaty first adopted in 1961 and revised in 1996.
In May, the Green party in France tabled an amendment to a law on the family but it was eventually withdrawn.
- 'Collective debate' -
Even before the judgement, the controversy has been revived in France, with the minister for the family, Laurence Rossignol calling for a "collective debate" about "the usefulness of corporal punishment in the education of children."
However, this will "not be enshrined in the law", Rossignol told AFP, so as not to "cut the country into two camps -- for and against smacking."
"For abusive parents, we have a penal code. For those that occasionally resort to corporal punishment, we need to help them do things differently and not discredit them by saying 'the judge is coming to deal with that'," added the minister.
Polls show widespread support in Britain and France for the right to smack children.
The subject came to the boil in France in 2013 when a father was fined 500 euros ($600) for smacking his nine-year-old son.
Some people lauded the ruling, others found it disproportionately harsh.
Pope Francis raised hackles earlier this year when he said good fathers knew how to forgive but also to "correct with firmness".
He described as "beautiful" and dignified the response of one father who said he sometimes smacked his children "but never in the face so as to not humiliate them."
A former education minister for the opposition UMP party dismissed the debate.
"Is this really the debate of the century? Stop it, there are more important subjects," said Luc Chatel.
Those in favour of a complete ban point to the mental and physical harm suffered by the child.
Gilles Lazimi, from the campaign group "Foundation for the Child", said that smacking a child is "not only ineffective but also harmful for the health of some children."
Being hit can "interfere with brain development, emotional development, the relationship with parents and ... as the child ages, can result in a loss of self-confidence and self-esteem," said Lazimi.
However, another opposition politician, Jean-Christophe Lagarde, said it was "ridiculous" to introduce laws that governed family life to that extent.
"Are we going to be told how to stack our plates, whether children should be made to dry up and whether they can help their parent with the chores?" he asked.
Unlike the European Court of Human Rights, the Council of Europe does not have the power to punish its members, only to slap them on the wrist.