Sounds as though Legoland is just as screwed as Chessington at the moment (if not more), strict council, opposing locals, difficult getting planning permission and that isn't a lot of space left for development and expansion, not to mention most of the park is made from Legoland staples.
Judging from situations, the only uk Merlin park which seems to get most things granted and appear to have good relations with the local council is Thorpe. I just wish Moorlands, Kingston & Windsor councils would just wake up and see the parks as major tourist pulling attractions which benefit the local economy.