Extinction Rebellion says it is not planning any action that would force the airport “to pause any summer flights”.

The climate change activist group brought parts of central London to a standstill earlier this summer with a series of protests and occupations.

According to a leaked internal memo, the group is understood to have considered disrupting operations at Heathrow by using drones.

Its action had been due to start on 18 June and continue for a further 10 days in July to protest against plans to expand Heathrow airport with a third runway.

The group branded suggestions members were willing to endanger the lives of others “a depressing and predictable smear”.

However, the group added Heathrow had not been removed from its strategic planning.

Heathrow said the potential action was “reckless”, while the Met Police said any efforts to endanger the safety of an aircraft carried a penalty of life imprisonment.

In a statement, Extinction Rebellion said: [We] will not be carrying out any actions at Heathrow Airport in June or July this year, aimed at causing disruption to holidaymakers and those planning to use the airport in this period. The Heathrow Airport authorities will therefore not have to pause any summer flights.”

Operations at Heathrow airport were suspended for around an hour in January due to drone activity.

It came just weeks after Gatwick airport was forced to shut down for around 36 hours due to drone activity in and around the airfield.

The government has since rolled out new powers to police to combat illegal or dangerous drone activity, and has extended the no-fly zone around airports to deter drone activity.