France’s Energy and Environment Minister Nicolas Hulot resigned from Emmanuel Macron’s government, saying the president’s administration has made only “small steps” in protecting the environment and has failed to question the use of nuclear energy.

“I don’t want to lie anymore,” Hulot, a former television star turned environmental activist, said on France Inter radio, adding that he felt he had been unable to help the environment in his ministerial role. He said he hadn’t notified the president or the prime minister ahead of his radio announcement.

Hulot, a vocal environmentalist for decades in France, was one of the most prominent ministers in Macron’s government and his sudden resignation is a blow to the president. Hulot said Macron wasn’t forceful enough on pesticides, biodiversity protection or land destruction among other causes he sought to promote, according to Bloomberg.

Hulot’s resignation comes as the government is preparing its energy policy road map for the next 10 years, which aims to reduce the use of nuclear power. Electricite de France SA is at the same time trying to convince Macron to agree to new atomic plants to replace part of its aging fleet. France is “persisting” in a nuclear industry that’s a “useless madness, economically and technically,” Hulot said. “I haven’t managed to convince in all those issues.”

The resignation took place hours after Macron met with hunters, and granted them more rights. Hulot also attended the meeting.