National Highways has been granted an injunction against M25 protesters, which will come into effect this afternoon and means activists will face possible imprisonment, Transport Secretary Grant Shapps said.

       Home Secretary Priti Patel and Mr Shapps vowed to ensure "guerrilla" activists "cannot keep disrupting and endangering people's lives".

       The legal action came after members of the environmental group ran into moving traffic on the M25 at junctions 9 and 10 on Tuesday, prompting police and the AA to warn the "dangerous" behaviour "put lives at risk" and could cause "multiple fatalities."

       Ms Patel said the "important injunction" would mean "people can get moving again" on the M25.

       "We will not tolerate lives being put at risk," she said. "Those who continue to do so risk imprisonment."

       Mr 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."

       Any breach of the injunction would be Contempt of Court with a maximum jail sentence of two years, a serious enough offence for police to be able to remand protesters in custody and prevent them causing further disruption.

       Footage taken at the scene by LBC showed the protesters walking on to the motorway and sitting down on the ground in front of moving traffic.

       The M25 climate protests have also prompted anger from a police chief for putting officers in danger after they shut down the motorway five times in just over a week, as the police back the injunction.

       The Assistant Chief Constable from Humberside Police has said that police officers "should not have to patrol the M25 waiting for protesters to turn up".

       Chris Noble, 43, told BBC Radio 4's Today programme: "The people most likely to come to harm at the moment are probably police officers for having to run across motorways, try and remove protesters as well as ironically keep them safe from themselves."

       George Eustice, the Environment Secretary, told Sky News on Wednesday: "We are taking legal action, I understand, to seek an injunction that would give police stronger powers to be able to intervene pre-emptively to stop these protests happening so that you are not getting a situation where you have to wait for them to sit on the road, cause chaos and then have to remove them after the event."

       Mr Eustice acknowledged the protests were "very frustrating for people trying to get to work, go about their business".

       One of the activists, Zoe Cohen, told the Today programme on Wednesday that "safety has been foremost in our minds" and that the protesters involved "understand the risks they are taking".

       She said: "The people taking part in these actions understand that the risks they are taking are because we have tried everything else to make the Government protect us from the predicted impacts of climate chaos."

       Ms Cohen added that the "last thing" they want is for someone to come to serious harm.