For something that's going to create homes (such as many of the new towns that have popped up, Camborne being last one I worked on personally) or if it's going to create huge amounts of jobs (Magna park near Lutterworth for example) yes. But the chances of building a football stadium on greenbelt when there's an empty stadium in the vicinity of where the club should be playing? I doubt it.
For something that's going to create homes (such as many of the new towns that have popped up, Camborne being last one I worked on personally) or if it's going to create huge amounts of jobs (Magna park near Lutterworth for example) yes. But the chances of building a football stadium on greenbelt when there's an empty stadium in the vicinity of where the club should be playing? I doubt it.