CAMPAIGNERS against the expansion of Heathrow airport have vowed to take direct action if the Government presses ahead with the controversial plans.
Protesters will carry out marches, demonstrations and 'flash mobs' if the Government does not back down.
The decision was made at a conference held last Saturday to plan for the 'worst case scenario' in addition to the ongoing campaign to lobby MPs and government departments.
A decision over expansion plans is expected later this year.
About 140 people attended Harlington Baptist Church, in High Street, Harlington, where the message was reiterated: they were not prepared to let the village of Sipson be wiped off the map, as it would be if a third runway were built.
The direct action will form part of an autumn offensive by the anti-expansion campaigners.
They will highlight the effect expansion will have on people's health and on children's education.
There will also be further work to challenge the argument that expansion of the airport is required for economic reasons.
The declaration came as a study commissioned by the City Of London Authority was published, saying a third Heathrow Airport runway was the obvious solution to airport congestion.
John Stewart, the chairman of one of the anti-expansion groups, HACAN, said: "The message that came across very clearly from the conference is that people are utterly determined to stop any further expansion of Heathrow.
"They don't want a third runway or a sixth terminal and they don't want more planes on the existing runways."
The event was organised by HACAN, No Third Runway Action Group (NoTRAG), the Camp for Climate Action and Greenpeace. Speakers included Christine Taylor from NoTRAG and Hayes and Harlington MP John McDonnell (Lab).
Speaking afterwards, Mr McDonnell said: "We have basically shaped the campaign for the next six months.
"It was an incredibly well attended meeting and the message which came out of it was very positive indeed."