I agree that you can't extrapolate from one single country but being overpopulated doesn't help. Life has become inordinately stressful and the bin man is probably doing the work of someone else in addition to his own. Neighbours no longer communicate as they once did. Maybe if politicians had told the indigenous population in the 1960s that they would have to pull together a bit more as they did during World War 2 instead of importing millions of immigrants which brought their own problems in their wake we wouldn't be in the mess we are now.
Based on the amount of times our small island has been invaded, I'll hazard a guess that very few of us are pure anything, let alone Anglo Saxon. Certainly, by refusing more immigrants, it would enable subsequent governments to persuade into work those who would prefer not to, but I think more effort will need to go into keeping hold of those with good qualifications, rather than allowing them to emigrate to obtain better pay and life style. I clearly recall, whilst I was in college, being shown the large and colourful posters which were sent to various countries inviting them to come here. They showed a beautifully attired black lady, complete with tiara, standing in a modern and sparkling kitchen. There were her two, finely dressed children sitting round a table bearing, probably, more food than they'd see in a month in their own country. All illusion, of course. They ended up in Rachman type properties doing the work that we felt was beneath us. Don't misunderstand me. I'm not suggesting we should allow people free rein to come here as they choose without having jobs to go to -it's not allowed in Australia- but if people are willing to come over and contribute, I can't see why we'd wish to prevent it.