France's top court has blocked a bill banning social media access for under-15s, saying it infringes upon freedom of expression.
The move is a setback for President Emmanuel Macron, who asked his government on Friday to rewrite the legislation.
The legislation would have barred children younger than 15 from opening a social media account from September 1.
Accounts already open would be closed within four months by social media platforms, which would also need to use age verification approved by the French privacy regulator.
But France's Constitutional Council said that the bill, while requiring everyone to give proof of age, failed "to specify the conditions and limits" under which it should be provided, as well as infringing on freedoms and privacy.
"The Council holds that the contested provisions, on the one hand, disproportionately infringe upon the freedom of expression and communication and, on the other, fail to provide the legal safeguards necessary to ensure the right to respect for private life," it said.
French MPs had approved the bill in July, becoming the first in Europe to follow Australia, whose ban barred access to platforms including Facebook, Snapchat, TikTok and YouTube for under-16s in December.
MPs there are considering stricter penalties after data showed mixed success.
Countries around the globe including China, the United Arab Emirates and Turkey have either instituted measures intended to curtail or bar access to social media for young people or have said they were planning them.
The European Union has said it was planning to seek stronger protections for children from harmful social media features.
Social media companies generally oppose blanket bans, saying they have measures already in place to protect younger users, including age restrictions, although they have also said they would comply with government bans.
Macron, who in April urged teenagers to turn off their devices and read in order to become better citizens, has ordered Prime Minister Sebastien Lecornu to rework the draft legislation to take the Constitutional Council's concerns into account, the Elysee said in a statement.
The government said Macron was determined the reform take effect before the northern hemisphere spring 2027, when France holds a presidential election.
Macron cannot run for a third term.
