Lewdown Holdings have won an eviction action against Grow Heathrow, who were squatting a disused market garden in Sipson.
The anti-Heathrow campaigners originally moved in to the five acre site in 2010. Now the High Court has granted Lewdown possession of the land and ordered the campaigners to leave in 14 days.
Grow Heathrow say they have grown much of their own food on the site, and use energy from renewable sources. Lewdown Holdings have had several planning applications for developments on the site refused.