National Highways has been granted a court injunction, meaning similar protests on the motorway could lead to imprisonment.
Transport Secretary Grant Shapps tweeted: "Invading a motorway is reckless & puts lives at risk.
"I asked National Highways to seek an injunction against M25 protestors which a judge granted last night.
"Effective later today, activists will face contempt of court with possible imprisonment if they flout."
The action against Insulate Britain comes as Home Secretary Priti Patel and Shapps vowed to ensure 'guerrilla' activists 'cannot keep disrupting and endangering people’s lives'.