Hmm, London still needs the services of those poor that you speak of. If people are willing to pay the exorbitant prices for having a home there, I don't see why they can't be prepared to pay more to get the basic services running.
The further London moves away from the UK, the more are cities like Brighton, Cambridge etc. looking more attractive. More attractive to people willing to live in a more mixed area too.
Come to brighton! We have a nice little tech hub style arrangement going on, it just lacks a fancy silicon-related name because it isn't built on billions in government funding.
BTW,
>You would end up with a 'walled garden' of elite living in London and the poor / unemployed living outside. The city would lose it's unique cultures, become even more gentrified / elite than it currently is and social unrest could start to occur.
This is already happening/has already happened, unfortunately.
The further London moves away from the UK, the more are cities like Brighton, Cambridge etc. looking more attractive. More attractive to people willing to live in a more mixed area too.