INSULATE Britain activists targeted a busy London roundabout and blocked the M25 this morning, bringing traffic to a standstill during rush hour. 

The group said that about 40 people were involved in the joint action at junction 25 on the M25 in Hertfordshire and Old Street roundabout in east London.

Several protesters also glued themselves to the road. 

By midday, police said that both roads had been reopened after officers arrested 19 people at Old Street and 16 activists on the M25.

The Metropolitan Police said that all were arrested for obstructing the highway. 

The action was the 12th day of protest in the last four weeks as part of the group’s ongoing campaign of disruptive civil disobedience to pressure ministers to insulate all homes in Britain, starting with the poorest. 

The group said that the action on the M25 likely broke an injunction obtained by Highways England, which means they could face prison sentences. 

Condemning the protests in an interview with LBC radio, Transport Secretary Grant Shapps said: “It’s dangerous, it’s really outrageous, and actually, ironically, it probably adds to pollution as cars idle, waiting for their nonsense … for them to be unglued from the road.”

He then called for a toughening up of laws to “get these glued fools off the road.” 

But Insulate Britain member Tracey Mallagan said: “If governments don’t act soon to reduce emissions, we face a terrifying situation. 

“We won’t be worrying about shortages of pasta or loo rolls because law and order breaks down pretty quickly when there is not enough food to go round. 

“The government won’t be wondering if there are enough hospital beds or ventilators, but whether there are enough people left to bury the dead.”