Heathrow protestors in stupid shocker?

Am I missing something or have those protesting against the third runway at Heathrow completely ignored the very likely issue of a Compulsory Purchase Order? For those that aren't up to date with the situation basically a new runway is planned for Heathrow and in an attempt to stop it happening protestors have bought land on the site. However if the council continues to back the proposal then they can simply issue a CPO and force through the sale of the land, hence the protestors are wasting their time. Rant over.