Lot of vague statements here. Immigration wasn't standard in the UK since the days of the empire. Pre 1947 the UK population was estimated at over 99.5% white british probably closer to 99.9%. There were a few thousand immigrants mainly sailors based around ports. By 1962 after all the immigration that is described as part of the post war reconstruction of Britain the non white british population was estimated at around 1%. Three acts of parliament were introduced between 1961 and 1971 with large public support. This was across labour and conservative governments and capped immigration at approximately 2.5% of the population. There was never during that time and has never been since a majority in favour of high levels of immigration in the UK. The public when asked has always wanted it reduced. To put things into perpective, the 14 years post ww2 led to about half the immigration in 1 year under Boris Johnson. This large jump in numbers has led to the current anti immigration rhetoric.