Heathrow climate change protest 'Plane Stupid' causes major delays approaching airport

Travellers warned that three activists are causing tailbacks to the M4

British Airways has cancelled 26 flights during the afternoon and evening (Getty)

Three climate change activists protesting against the building of a new runway at Heathrow have blocked off a tunnel to the airport, causing major delays.

Police were called to the scene but have yet to make any arrests, while video posted to social media showed a white van blocking both lanes approaching the UK's main air travel hub.

The activists, from the campaign Plane Stupid, appeared to have locked themselves to their van. They displayed a banner with the slogan: "No ifs, no buts: no third runway."

The protest was largely met with derision and anger on social media. James Clark wrote: "Remember when protests were designed to earn sympathy? Plane Stupid, the original and still stupidest protest group."

In a statement, Scotland Yard said officers were called about the incident at 7.42am this morning. According to LBC, a contraflow has been set up to allow some people through the tunnel - but tailbacks stretch as far as the M4.

A spokesman for Plane Stupid, Cameron Kaye, said: "Airport expansion would wreck the legally-binding Climate Change Act, risking wiping out 55% of species this century and displacing 75 million more people from their homes by 2035.

"If aviation growth isn't reduced, by 2037 aviation alone could emit all of the carbon it's safe for the UK to emit. The government needs to choose: build new runways or stop climate chaos: it's that simple."