France's Constitutional Council has struck down a law that would have banned children under 15 from social media, ruling that it violates freedom of expression — a setback for President Emmanuel Macron, who had made the measure a flagship of his remaining time in office.

The law would have taken effect on September 1, requiring minors under 15 to prove their age before opening an account, and closing accounts already open. France would have been the first European country to follow Australia's world-first ban, which since December has barred under-16s from platforms including Facebook, TikTok and YouTube.

The Constitutional Council found that the ban "inherently requires every person, even an adult, to prove their age before accessing certain online services." Because the law failed to specify the conditions and limits of that proof, the court said, it did not establish the legal safeguards necessary to protect freedom of expression. The council struck down the most contested provisions while leaving other parts of the law standing.

Macron has ordered Prime Minister Sébastien Lecornu to rework the draft legislation in light of the council's concerns. The Elysée said Macron was determined to have the reform in place before spring 2027 — ahead of the next presidential election, for which he cannot run again.

The ruling carries weight well beyond France: it is the first major judicial review of a European-style ban on minors' social media access and is likely to shape debates in other capitals considering similar age limits. It also highlights the technical and legal difficulty of age verification online, which privacy advocates have criticized for years.