Surrey’s police and crime commissioner has warned it is “very difficult” to charge M25 environmental protesters after the same junction on a motorway was blocked twice in one day.
Insulate Britain has been targeting the M25 over the past seven days as it calls on the government to insulate all UK homes by 2030 to cut carbon emissions.
Despite an injunction being obtained by the government against the group, they caused disruption on a roundabout at junction 3, the Swanley Interchange in Kent, at about 7.30am, by gluing themselves to the road.
Police arrested 11 people on suspicion of obstructing the highway and conspiracy to commit criminal damage before closing the demonstration.
However, the group returned at 1pm resulting in a further 16 arrests for the same offence.
All 27 people are now being held in custody.
Surrey Police and Crime Commissioner Lisa Townsend said officers "doing their utmost to prevent the disruption".
But she also said it was "unfair" that the police were being blamed for not charging the protesters, which meant would be able to return to the M25.
She said: "It has been very difficult for the police because if they charge the protesters with a relatively minor offence, it is likely to be discontinued.
"If they try to elevate the charge to a more serious one, they are finding it is not reaching the necessary threshold.
"The public deserves to see a response from all parts of the criminal justice system and it is unfair for the police to be blamed if people do not end up before the courts."
The High Court injunction granted last week aimed to prevent people from blocking the motorway, otherwise they could be found to be in contempt of court.
This carries a maximum penalty of two years in prison or an unlimited fine.
However, Insulate Britain did not seem deterred, saying in a statement: "We are going nowhere. You can raid our savings. You can confiscate our property. You can deny us our liberty and put us behind bars.
"But shooting the messenger can never destroy the message: that this country is going to hell unless you take emergency action to stop putting carbon into the air. Boris get on with the job."
The protesters have blocked other important routes over the last week, including the A1(M) and A20 near the Port of Dover.
Posting on social media on Wednesday evening, Transport Secretary Grant Shapps said the government are increasing punishments for those who "repeatedly put lives in danger" through such actions.
"Reckless protesters who repeatedly put lives in danger on the M25 have already had knocks on their doors," he said.
"We are serving papers and those who continue these idiotic, dangerous and counter-productive demonstrations will be caught and face unlimited fines or prison."