Five climate change activists have been arrested, after blocking the main entrance tunnel to Heathrow Airport and causing traffic chaos on surrounding routes.

Three members of Plane Stupid, an anti-expansion campaign group, parked a vehicle across both lanes of the entrance tunnel and locked their bodies to it, unfurling a banner quoting David Cameron's election promise: “No Ifs, No Buts: No Third Runway”.

They arrived at around 7:40 this morning (November 26) and traffic has since come to a standstill.

A Metropolitan Police spokesperson said: "Officers are currently dealing with a protest near the inbound tunnel of Heathrow airport.

"They were called at 07:42hrs on Thursday, 26 November. Five arrests have been made."

This is the second time the tunnel has been blockaded in protest, after Harmondsworth resident, Neil Keveren, parked a van and stood on top of it earlier this year.

Mr Keveren said: "No one wants to do this, they feel they have to.

"People feel they have no choice. After we campaigned for years, David Cameron was elected promising 'no ifs, no buts, no third runway.'

"In 2010 the High Court ruled third runway plans “untenable in law and common sense” because they breached the Climate Change Act. Now Cameron might just build it anyway. We have tried every other option. We have been forced to be disobedient just to be heard. To save our homes and our planet.”

Plane Stupid previously caused 22 flights to be cancelled at the airport, after entering Heathrow's north runway and forming a 'human chain' on July 13.

Cameron Kaye, a Plane Stupid protester, 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.

“There is already airport capacity for families taking their yearly holiday. New runways only benefit the 15% of flyers who take 70% of our flights, cooking our planet. These are rich frequent leisure flyers. The most reliable predictors of frequent flyer status are a household income over £115,000 and owning a second home abroad, but it's the poorest people who suffer most from climate change.”

On 13th July Plane Stupid blocked Heathrow's North runway, reportedly causing 22 flights to be cancelled and hundreds delayed.