Environmentalists have bought some land in an effort to stop the expansion at Heathrow. I think they are misguided: that airport expansion isn’t really a problem for the environment. But I do think owners of land have a right to their property. So if the government tries to use compulsory purchase to allow the expansion to go ahead, I will be on the side of the environmentalists.
Of course, I also think that anyone should be able to buy some land and build an airport on it. Environmentalists would disagree with me and would say that it is okay for the government to decide what people can use their land for. So if the government wanted to be really clever about this, perhaps it could just designate the plot of land as for air transport infrastructure use only, and then fine the owners for growing vegetables on it.