Insulate Britain urged drivers to avoid the M25 during Wednesday morning's rush hour or drive on the motorway at 20mph as the campaign group planned its next protest.
Environmental campaigners said they were not worried about "endless injunctions" including new national restrictions imposed on Monday aimed at stopping disruption.
The group said it had declared the M25 motorway a site of "non-violent civil resistance" and warned drivers to stay away or reduce speeds to reduce the risk of accidents.
In a statement, Insulate Britain said: "Starting from 7:00 on the morning of Wednesday 27th October the M25 will become a place of nonviolent civil resistance.
"Insulate Britain acknowledges the inconvenience and irritation we are causing to the public in our campaign, we ask that you understand that the days of disruption are necessary to force a government to fulfill its most basic of duties to protect and defend its people."
A new nationwide injunction was granted against Insulate Britain protesters which means they could be jailed if they block any motorway or major A road across England.
The new injunction, secured by National Highways, bans protesters from obstructing traffic and prevents access to 4,300 miles of motorways and major A roads, according to the Department for Transport.
It also prohibits activists from gluing themselves to the road, damaging the road surface and abandoning their vehicles.
Another team also blocked Liverpool Street - one of the busiest commuter areas in London.
Campaigners of Insulate Britain are demanding the government carry out a comprehensive retro fit of all UK homes to insulate the homes of the poorest people.
The aim is to ensure lower energy bills and warm homes for the most vulnerable and to reduce carbon emissions.
It claims insulating all homes is the "most cost effective way" to reduce the impacts of fuel poverty and reduce CO2 emissions.