Nine Insulate Britain protesters could face fines or even jail time if they are found to have breached injunctions by blocking the M25.
National Highways has confirmed it has made nine applications to the High Court for contempt of court against the activists.
Insulate Britain, which wants all homes to be insulated by 2030, have blocked roads and even motorways on multiple occasions, including in Hertfordshire.
M25 junctions at Kings Langley, Chorleywood, and South Mimms have been targeted, as has the M1 near Watford and by the A1 in Hatfield.
The group's tactics to sit in the road - and even glue themselves to the surface - have caused major frustration and anger for drivers prompting the Government to seek court injunctions to stop them blocking the road in certain places, such as the M25.
Dozens have been arrested - many multiple times - and in some cases, the injunctions weren't enough to stop sit-down protests.
Last night, National Highways (formerly Highways England) issued an update on proceedings against Insulate Britain protesters.
A spokesperson said: "National Highways is now taking the first group of activists from Insulate Britain to court, for breaching injunctions by blocking the M25.
"We will continue working with the police to bring those who carried out dangerous and disruptive action to justice.
"Those activists will now receive a court summons and could face imprisonment and/or an unlimited fine.
"Timings are now in the hands of the court but we expect hearings will take place as soon as possible."
National Highways confirmed that so far nine applications for committal have been made to the High Court.
The court will need to decide whether members of the environmental campaign group breached orders that were made earlier this month.
Protesters could face fines and even jail time if found to be in breach.
It is not clear which incidents the nine activists are linked to. According to court documents from an earlier hearing, 112 people have been served with court orders related to the Insulate Britain protests.
Members of Insulate Britain were previously made subject to three other injunctions granted to National Highways, banning demonstrations on the M25, around the Port of Dover and on major roads around London.
On Tuesday, a judge at the Royal Courts of Justice extended an injunction granted to Transport for London (TfL) against Insulate Britain.
Insulate Britain protests have been suspended since October 14 ahead of the United Nations COP26 climate conference in Glasgow, with the group also "profoundly" acknowledging the disruption it has caused.
However, the temporary halt is only set to last until this Monday (October 25), with police bracing themselves for further protests.
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