Organisers spent months planning it. The media ran news stories and features in the run up to it. Although it was estimated 20,000 people would turnout for the Make a NOise carnival march against the Government's plans to expand Heathrow, just 5,500 people showed up.

Studies carried out by Richmond and Hounslow councils earlier this year found about 90 per cent of residents were opposed to expansion.

With just 25 per cent of those expected to turn up attending last Saturday's (March 31) march to Sipson to spell out a giant human no,' it has left some asking why more people did not vote with their feet.

West London's leading campaigner against expansion at Heathrow, John Stewart, chairman of the climate group Hacan, was satisfied with the turnout but said: "There does seem to be this reluctance on behalf of people who are very clearly against expansion at Heathrow and who would lose out personally by it, to actually come out, to set aside the time to take action."

Head mobiliser for the Make a NOise carnival, Tamsin Omond, one of the Westminster five' who protested on the roof of parliament admitted she was "incredibly optimistic", but that she was "expecting huge numbers".

She said: "If you are angry with it then you need to put your body where your voice is. If that were the case we would have had hundreds of thousands of people."

She added her concern that people expect to have an easy ride and that Greenpeace, 2M Group and their boroughs will do all their work for them.

Clive Soley, campaign director of pro airport expansion group Future Heathrow, said he was not surprised with the low turnout.

He said: "Opposition groups are right in saying there is a significant voice against, but what's it's not doing is gathering up enough of the public.

"That's their problem. They have fooled themselves into thinking they are in the majority, but it is not the majority view of the people who live around the airport."