Heathrow Pause, an offshoot of Extinction Rebellion, has threatened to operate toy drones in Heathrow’s restricted airspace starting at 3am on 13 September.

The group says it expects between 50 to “a couple of hundred people” to be involved, each operating a drone. Their aim is to cause disruption for several days.

“From 13 September, we will exploit a loophole in Heathrow airport’s health and safety protocols and fly toy drones within its restricted zone,” the group said.

“It is our understanding 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.”

The group added they would do so knowing they will be arrested, prosecuted and likely face “significant prison sentences” for their actions.

“We have lives, we have families, we do not wish to go to prison,” said the group. “But we are steadfast in our resolve. We do this in defence of life. We do it because our consciences leave us no other choice but to act.”

Heathrow, while acknowledging the need for action on climate change, has branded the proposed action criminal and counter-productive.

“This is a global issue that requires constructive engagement and action,” said a spokesperson. “Committing criminal offences and disrupting passengers is counter-productive.”

Deputy assistant commissioner Laurence Taylor of the Met Police said the force would do “everything in its power” to prevent any such “criminal activity”.

“Heathrow Airport is part of our national infrastructure, and we will not allow the illegal activity of protestors to cause misery to thousands of air travellers,” said Taylor.

“The dangers of flying drones in airspace used by airliners carrying passengers are stark and the consequences potentially very severe. Anyone caught illegally using a drone can expect to be dealt with in line with the law.”

In a statement, Extinction Rebellion said it neither condones nor condemns the action, but would not be supporting it.

“While Extinction Rebellion UK recognises the need for actions that are highly disruptive and controversial in order to highlight the severity of the climate and ecological emergency, Extinction Rebellion UK does not support an action at Heathrow as designed at this time,” said the group.

“If such an action takes place at this time, it will be independent of Extinction Rebellion UK. Those that choose to become involved do so as individuals just as they can become involved in other social movements and networks separate to Extinction Rebellion.”

Heathrow Pause is due to meet with the police and airport authorities on Friday to discuss their plans, The Guardian reports.