Clearly emotional, Hulot made clear his frustrations at what he said was France's slow pace of progress on green issues. The long-time environmental advocate told France Inter radio that he no longer wants to give the impression "that we're up to standard on these issues, and so I have decided to quit the government."
Recruiting Hulot to his government had been a coup for Macron, who has sought to position France as a champion in the fight against environmental degradation and as a counterweight to the climate change attitudes of U.S. President Donald Trump.
Losing Hulot so suddenly, just as the government is resuming work after France's August vacation, is likely to force a ministerial reshuffle but also casts doubt on the strength of Macron's commitment to "make our planet great again."
Hulot damned Macron's government with faint praise as he sprang his resignation surprise.
"France is doing more than a lot of other countries. Do not make me say that it is doing enough. It is not doing enough. Europe is not doing enough. The world is not doing enough," he said.
Never a career politician, Hulot accepted a role in Macron's government in the hope that, from an inside position, he could make real progress on green concerns that he has long sounded the alarm about.
But on France Inter, Hulot said short-term pressures were taking priority in government over the longer-term need to reverse environmental destruction. He described himself as "all alone" and said: "I have a bit of influence but I have no power and no means."
Hulot said he'd been mulling his resignation for several months but one of the last straws was a government meeting Monday about hunting. Hulot was dismayed that a hunting lobbyist was allowed to take part despite not being invited, seeing his presence as a symbol of lobbyists' influence over French government.
"I no longer believe," Hulot said.