TWELVE opponents of Heathrow Airport’s expansion occupied the northern runway yesterday by chaining themselves to railings and binding themselves together.

Six protesters were arrested after activists from Plane Stupid cut through the perimeter fence at 3.30am and caused flight delays and 13 cancellations over three hours.

Three bolted their necks onto the metal barricade with cycle locks, but these were cut off by police who arrived on the scene with angle grinders.

Officers struggled to separate at least four others who lay on the damp asphalt fixed in pairs by dense layers of wire mesh, electrical tape and thick plastic tubes over their arms.

Plane Stupid spokeswoman Kirsty Jones said that the direct action was in response to Prime Minister David Cameron’s U-turn on his 2010 promise not to add a third runway to Heathrow.

She said: “This is yet another example of how we cannot trust the Tories or any of their promises on climate change.”

Condemning Britain’s poor contribution to the fight against global warming despite pledges by the government, Ms Jones said this “is not going to reflect well on the UK” at the United Nations climate change conference in Paris later this year.

Hayes & Harlington MP John McDonnell said he expected more protests, demonstrations and occupations in the mass campaign building against the runway, which is set to cost at least £18 billion and lead to the demolition of around 800 homes.

He said: “People will not stand by and allow our communities to be demolished, our air to be poisoned and millions to be blighted by noise and climate change destroying our planet.”