Land earmarked for the construction of a controversial third runway at Heathrow airport has been bought "under the noses" of the Government by a coalition of green campaigners, celebrities, scientists and politicians.
Environmental campaign group Greenpeace said the move threw a "huge spanner" into the expansion plans, warning that the site would become a focus for protesters.
Oscar-winning actress Emma Thompson and impressionist Alistair McGowan are among those who announced they had bought the piece of land, the size of a football pitch, from a local landowner for an undisclosed fee.
The site is close to the village of Sipson, which would lose hundreds of homes if the airport expansion went ahead.
The deeds have also been signed by Conservative Party green adviser Zac Goldsmith and Greenpeace director John Sauven, while beneficial owners who have also signed-up include local Labour MP John McDonnell, Conservative front bench spokeswoman Justine Greening, Liberal Democrat MP Susan Kramer and Royal Society Research Fellow Dr Simon Lewis.
Greenpeace said it was inviting members of the public to become beneficial owners and pledge to do what they can to defend the land from the Government and BAA, under the campaign banner Airplot.
Mr McGowan said: "BAA were so confident of getting the Government's go ahead, but we have cunningly bought the land they need to build their runway.
"Now that we own it, we'll never sell it to them and we're confident that we'll be joined by people from all over the world who will help us defend it.
"No government which is serious about tackling climate change would ever think of expanding Heathrow, and because we care about our planet's future and our children's future, we are not going to let them.
Ms Thompson said: "I don't understand how any government remotely serious about committing to reversing climate change can even consider these ridiculous plans. It's laughably hypocritical. That's why we've bought a plot on the runway. We'll stop this from happening even if we have to move in and plant vegetables."
