An Extinction Rebellion splinter group is threatening to cause chaos at Heathrow with plans to fly toy drones to disrupt flights.
The new group, called Heathrow Pause, plans to force flights to be grounded by flying toy drones in the restricted zone from September 13.
The threat flies in the face of warnings from police that drones targeting the airport could be treated as terrorist acts with life jail sentences if found guilty.
If carried out, the drone protest could take place in the middle of a three strikes planned by British Airways pilots on September 9, 10 and 27.
Members of the group say they know they will be arrested and acknowledge they face “significant” prison sentences but, in a statement issued on Thursday morning, said they were “steadfast in our resolve.”
They suggested “somewhere between 50 to a couple of hundred people” would be involved in the action, with each person using a drone.
“We do it because our consciences leave us no other choice but to act,” they said.
“From the 13th September, we will exploit a loophole in Heathrow airport’s health and safety protocols and fly toy drones within its restricted zone.
“It is our understanding that the airport’s authorities will respond by grounding all flights. Drones will not be flown in flight paths and there will be no risk of harm to anyone.”
A Heathrow spokeswoman said airport chiefs “agree with the need to act on climate change”, adding: “This is a global issue that requires constructive engagement and action.
“Committing criminal offences and disrupting passengers is counter-productive.”
A Metropolitan Police spokesman told the Daily Telegraph: “We are aware of reports of a protest planned at Heathrow airport on Friday, 13 September.
“Any drone flown into the path of an aircraft has the potential to cause great harm and endanger those on board.
“Anyone caught illegally using a drone within the proximity of an airport can expect to be dealt with in line with the law.”
Extinction Rebellion had threatened to fly drones over the base on dates in June and July unless the government dropped plans to expand the airport with a third runway but the action was postponed.