obieone You commented "another person should not expect to come in and grab whatever they fancy".
You say you have children working in other countries. Presumably in order to secure work, they had to compete with citizens of those countries to obtain a job. Either that, or they applied for jobs that are difficult to fill because those jobs are not attractive to the citizens of those countries. That is probably fair enough if they have not obtained citizenship of those countries, but if they are my understanding is that they should have exactly the same access to jobs and services as any other citizen.
Peaseblossom I too was born in London - Clapham to be precise and have lived in several areas in and around London and in other parts of England. My home for the last 27 years has been East London and I think you paint a very negative picture of it. My neighbours include Peruvian, Scottish, Jamaican, Rumanian, Irish, Pakistani, English, Granadian, Chinese, Polish, Mauritian and many other nationalities. We all get along pretty well and I would far rather live in a neighbourhood that is reasonably accepting of difference than the sort of narrow-minded, intolerant world of those who fear and resent anyone who is different from themselves.