The plan, announced today, is in protest of building a third runway at Europe’s busiest airport.
In December, a rogue drone flier — not believed to be a member of the group — caused misery at Gatwick Airport with 1,000 flights grounded in 72 hours of chaos.
Extinction Rebellion’s similar “nonviolent” plan is “not about targeting the public”, the group claimed.
With families due to jet off on holidays they have been planning all year, some climate change protesters fear the group’s new direction will alienate ordinary people.
“This is not about targeting the public, but holding the Government to their duty to take leadership on the climate and ecological emergency”
But others believe that governments will only treat the climate crisis with urgency if faced with large-scale disruption.
Extinction Rebellion said it will close Heathrow for 24 hours on June 18, followed by two weeks in July if the government does not cede to their demands.
“On June 18, we plan to carry out nonviolent direct action to ensure Heathrow Authorities close the airport for the day, to create a ‘pause’ in recognition of the genocidal impact of high carbon activities, such as flying, upon the natural world,” Extinction Rebellion said in a statement.
“This is not about targeting the public, but holding the Government to their duty to take leadership on the climate and ecological emergency,” the group said.
British security forces have been on alert since the drone incident in December.
Extinction Rebellion was not involved in that incident, senior members of the movement said at the time.
In an internal proposal written by volunteers and seen by Reuters, activists suggested using drones to force authorities to ground flights at Heathrow Airport while other protesters held picnics.
The activists said they would avoid any risk to planes and passengers by informing the authorities of their plans in advance.
Parliament backed a plan to build an £14billion third runway at Heathrow Airport last year, but the expansion faces opposition from local communities and environmentalists.