The French Constitutional Council said the law did not impose disproportionate punishments or prevent the free exercise of religion in a place of worship, finding therefore that "the law conforms to the Constitution."
"Given the damage it produces on those rules which allow the life in community, ensure the dignity of the person and equality between sexes, this practice, even if it is voluntary, cannot be tolerated in any public place," the French government said when it sent the measure to parliament in May.
Lawmakers have also cited security reasons for forbidding people from covering their faces in public.