Permenent separation is impractical and just stupid, however, I do wish immigration could be brought down to a much lower rate than it is now. I have no problem with qualified professionals immigrating to the UK, but the vast majority of immigrants are low-skilled, probably below average IQ menial workers. The UK does not need these people. Japan has the system that I think is most ideal, they pretty much only ever take skilled immigrants in. The least skilled people they take in are a few Filipina nurses, and nurses are still far more qualified than some toilet scrubber or burger flipper than the UK takes. Hell, you have to have a degree to even teach English in Japan.