"By the end of July, all the authorities within the (EU data protection) task force will have taken coercive action against Google," said CNIL president Isabelle Falque-Pierrotin.
Last year, Google consolidated its 60 privacy policies into one and started combining data collected on individual users across its services, including YouTube, Gmail and social network Google+. It gave users no means to opt out.
National European data protection regulators began a joint inquiry as a result. They gave Google until February to propose changes but it did not make any. Google met with the watchdogs several times and argued that combining its policies made it easier for users to understand.
The CNIL's move is seen by legal experts and policymakers as a test of Europe's ability to influence the behaviour of international internet companies.
Britain is still considering whether its law has been breached and will write to Google soon with its findings.
Google said it would continue to work with the authorities in France and elsewhere.
The scrutiny comes at a delicate time for Google after revelations that the US National Security Agency has secretly gathered user data from nine big U.S. Internet companies, including Google, to track certain individuals' movements and contacts over time.
The disclosures about the so-called Prism surveillance programme triggered widespread concern and US congressional hearings about the scope of the information gathering.
European citizens and their leaders have expressed outrage that they have no legal rights to protect themselves from such spying. President Barack Obama was forced to defend the surveillance programme at length during a news conference on a trip to Germany on Wednesday.