Protesters angry at the Government’s approval of a third runway at Heathrow airport have said they are “increasingly confident” the project will be scrapped after taking their fight to Gordon Brown’s doorstep last night.

About 150 people gathered outside Downing Street from 5.30pm to chant and wave banners in a demonstration organised by the Campaign Against Climate Change.

Residents held signs saying the decision “makes a mockery of the UK’s climate targets” and was a “disgrace to democracy”.

Labour MP John McDonnell, suspended from the House of Commons for picking up the speaker’s mace last month in protest at the third runway, reportedly told the crowd the future of Heathrow would be determined by demonstrations and direct action.

John Stewart, chairman of anti-expansion group Hacan, said: “The message of the demonstration was very clear. The fight against the third runway goes on.

"We are increasingly confident that the Brown Runway will never see the light of day.”

Other speakers included Richmond Park MP Susan Kramer, Green MEP Jean Lambert, Anna Jones from Greenpeace and Linda McCutcheon from the No Third Runway Action Group.

Meanwhile, pro-expansion campaign group Modern Movement - formed last month by a group of students and young professionals - held a counter-demonstration nearby.

About 40 members gathered on the corner of Parliament Square to chant slogans and make speeches, witnesses said.