The activists, believed to be part of Heathrow Airport-based Camp for Climate Action, targeted the building shortly after 8am.

Police community support officers arrived on the scene around 8.30am and were soon joined by up to 40 Metropolitan police officers who cordoned off the area.

Paramedics were called in to detach super-glued hands from the building’s revolving doors. Two protestors, perched on a platform above the doors, were removed onto a police scaffolding before being arrested.

One of those glued to the glass doors was taken to St Thomas’ Hospital with minor abrasions after losing skin on her hands, police told news website thisislondon.co.uk.

At time of going to press, the campaigners were believed to be planning a further series of “direct action” events at the Royal Bank of Scotland group offices in Liverpool Street and the Carbon Neutral Company in King’s Cross.

The Royal Bank of Scotland had been singled out for its links with Ferrovial – the Spanish private equity firm behind Heathrow owners, BAA – while the Carbon Neutral Company had been targeted for “profiting from climate chaos”, according to protestors.

The group was also allegedly planning to take over the back garden of Labour peer Clive Soley’s home in West London, owing to his position as campaign director of Heathrow Future, a pro-aviation expansion group.

Click here for the Camp for Climate Action website