Extinction rebellion protesters are threatening to disrupt flights at Heathrow Airport this summer

The environmental group has announced it will cause 10 days of disruption in July unless plans to expand the airport are scrapped.

Activists have held internal discussions about using drones to ground flights under plans described by Heathrow as ‘reckless’ and dangerous.

An initial one-day protest will go ahead on June 18 to ‘pause’ flights before a longer protest of ‘up to 10 days’ begins on July 1, Extinction Rebellion said.

‘Extinction Rebellion demands the Government begins to act on its declaration of a climate and environment emergency by cancelling all Heathrow expansion,’ a statement said.

The group described air travel as ‘genocidal’, adding: ‘The addition of the planned third runway would make Heathrow the single biggest carbon emitter in the UK; to expand the airport at this critical point in history would be madness.

‘We understand the action will cause disruption to a great number of holidaymakers, however we believe that it is necessary given the prospect of far greater disruption caused by ecological and societal collapse, if we don't act now.

‘Holidaymakers are being given advance notice to change travel plans.’

Baroness Vere warned: ‘Flying drones near an airport is a serious criminal offence and using drones to deliberately put people's safety at risk carries a maximum life sentence.

‘No Government has done more to reduce carbon emissions, and Britain is at the forefront of global efforts to tackle climate change.

‘Any illegal activity must be met with the full force of the law.’

The Department for Transport has said Heathrow expansion will only go ahead within the Government's carbon reduction targets.

A Heathrow spokeswoman said the protest plans are a ‘reckless action that if carried out could endanger the lives of the travelling public and our colleagues’.

‘We agree with the need to act on climate change, but that requires us to work together constructively - not commit serious criminal offences just as hardworking people prepare to spend a well-earned holiday with their family and friends,’ she said.