Third runway protest
Thousands attended the rally in Parliment Square to protest against a third runway at HeathrowChris Ratcliffe / Getty

Thousands of protestors have joined all five London Mayoral candidates, MPs and national organisations in Parliament Square, London, today for the largest ever rally against a third runway at Heathrow today, 10 October. The campaigners were part of a rally organised by the Heathrow Association for the Control of Aircraft Noise (HACAN).

Cabinet members are debating plans for a third runway after the Airports Commission's recommendation that Heathrow, rather than Gatwick, would be a better site to match rising demand for flights to and from the Capital. Campaigners believe that a new third runway will cause intolerable noise, breach EU limits on air pollution, cost millions in road improvements, and force thousands to move from their homes.

John Stewart, chair of HACAN galvanised supporters under the hashtag #no3rdRunway today on social media. He said outside Parliament Square: "it's a really great event, with a great turnout, Parliament Square is absolutely full, people have got their signs all over the place, people have come from all over London and beyond to send a very, very strong message to the prime minister.

"This is very much a cross-party objection to a third runway at Heathrow. I firmly believe we are going to win. It's too politically difficult to build a third runway at Heathrow"

Yesterday the Environmental Audit Committee said it would hear evidence on implications for noise, carbon emissions and air quality if the airport is allowed to expand. And the owners of Gatwick airport have continued to make the case for a second runway there instead.

MP for Richmond Park, Zac Goldsmith, described Mr Stewart as a "hero". He said: "We have people from every political party, Ukip, the Greens, Lib Dems, Labour, Conservative all the mayoral candidates – it's a real united front.

"I think we have won the arguments, I think we are winning the campaign. It's a magnificent turnout."

The Tory candidate for mayor added: "The environmental case against a third runway is devastating and makes expansion both legally and morally impossible. The economic case has completely disintegrated and I am confident that the Government will make the right decision."

Goldsmith joined other Mayoral candidates Sadiq Khan, of Labour, Sian Berry of the Green Party, Caroline Pidgeon, of the Lib Dems and Peter Whittle of UKIP. John McDonnell, Labour MP for Hayes & Harlington, Tania Mathias, Conservative MP for Twickenham also joined John Sauven, chief executive of Greenpeace, and Gina Parihar, head of legal at Friends of the Earth at the event.

But despite the protests, Rob Gray, director of the airport-funded Back Heathrow campaign, "This protest does not accurately reflect the views of most Londoners living near Heathrow Airport who back expansion," according to the Evening Standard.