The country as a whole benefiets from this type of structure/event
Sorry, but that is rubbish.
Most of what goes on in London only benefits London, and yet one way or another it is paid for by the rest of country.
What London really could do with is something rocket shaped .... but tipped with a 10 megaton nuclear device. And then perhaps the rest of the country would get some investment and be able to keep their own money for local causes.