Peterborough is my home city, it's not that bad really. I now live in Leicester, if immigration is really an issue to people it is much worse in Leicester with 50% + of the population being of non Anglo Saxon origins. TBH it has never bothered me, a good 50% of my clients are from South Asia, and I have always been treated with upmost respect and loyalty by my clients.
We have to be careful when we condemn non British people who migrate here and set up their own little communities. My experience of Brits who live abroad is that the majority will set up their own little British communities where they can talk about The English Premier League, eat bacon sarnies with HP sauce and have a nice cup of PG Tips or a pint of John Smith's. No one seems to complain about these ex-pat communities. I don't have a problem with any nationalities setting up their own groups and social events as long as they try to speak the language of their adopted country, obey the laws of the land and contribute to society in a positive way rather than just taking.