Extinction Rebellion protesters have been warned they could face life sentences if they use drones during a demonstration at Heathrow Airport.
The environmental campaigners plan to stage a protest at the airport on Tuesday next week.
Today Met Police chiefs issued a statement saying they were aware of rumours drones would be used to disrupt air traffic.
It comes after demonstrators descended on London earlier this year, blocking bridges and roads in the capital in a huge show of defiance.
The group has demanded that the government immediately addresses the world's climate change crisis.
Today Deputy Assistant Commissioner Laurence Taylor said: “There is speculation that protestors will use drones in order to disrupt business at Heathrow.
"I want to be absolutely clear that anyone caught illegally using a drone can expect to be dealt with in line with the law.
“If flown into the path of an aircraft, a drone has the potential to cause great harm to those on board. Affecting the safety of aircraft passengers is very different to blocking roads around London, and should this happen, the consequences will reflect the severity of the offence.
"Endangering the safety of an aircraft can result in a life sentence."
And he added: “As we have seen, the illegal use of drones at airports also has the capability to cause great disruption to the public, not only in London, but internationally. The airport is part of our national infrastructure, and we will not allow the illegal activity of protestors to cause disruption and misery to thousands.
“We will be deploying resources - both in terms of officers and equipment - to monitor the airspace around Heathrow and quickly detect and disrupt any illegal drone activity."
Mirror Online has contacted Extinction Rebellion for comment.
In April activists occupied four sites in central London - Oxford Circus, Marble Arch, Waterloo Bridge and Parliament Square.
