Boris Johnson has accused global warming campaigners of damaging their own cause by disrupting daily life with stunts like repeatedly blocking motorways.
Mr Johnson said that protesters from Insulate Britain who targeted M25 junctions in Kent, Surrey, Essex and Hertfordshire had detracted from the climate emergency message at a time when it is increasingly being taken on board by the British people.
And he said the government was right to take on new powers to move protesters when they threaten critical infrastructure like roads and railways or take direct action which risks doing “serious economic damage”.
Mr Johnson was speaking as 41 people were arrested in the latest Insulate Britain protests on London’s orbital motorway and other major transport links on Monday morning.
Climate activists blocked the anti-clockwise exit slip road at junction 18, Chorleywood, Herts, while a separate protest took place near junction four of the A1(M), near Hatfield.
A third incident saw Kent Police prevent protesters from gaining access to the M25 carriageway at junction 1a, the Dartford River Crossing.
Insulate Britain are calling on the government urgently to bring forward a legally binding plan to fund insulation retrofitting across the UK by 2030, as a means of cutting carbon emissions.
Founder Roger Hallam, a former Extinction Rebellion activist, has said he intends to humiliate Mr Johnson at the COP26 global warming summit which he is hosting in Glasgow in November, by showing that he is ready to jail hundreds of climate campaigners at the same time as urging world leaders to cut emissions.
Speaking as he travelled to the US for a crucial preparatory meeting ahead of COP26, Mr Johnson turned his fire on those responsible for three motorway blockades in the space of five days.
“I don’t think these people do any favours to their cause,” said the prime minister.
“I think what they do is detract from a very important moral mission that is widely shared by the people of this country.”
He said home secretary Priti Patel was right to demand that police take decision action against what she has termed “guerrilla tactics” by “selfish” protesters.
“We are taking powers to be able to move protestors when they are threatening critical national infrastructure when they are threatening to do serious economic damage,” said the prime minister. “I think that is absolutely right.”
Numerous arrests were made on Friday as demonstrators from the Insulate Britain group targeted M25 junctions in Kent, Surrey and Essex.
Ms Patel summoned Met Commissioner Cressida Dick and other police chiefs after officers failed to drag away protesters immediately when up to 80 blocked the motorway.
Transport Secretary Grant Shapps has branded the group’s actions as “dangerous and counterproductive”.
But Green MP Caroline Lucas said her party believes non-violent direct action is “legitimate when other forms of trying to raise issues with the government have failed”.
