I can assure you from decades of experience, dating back to the 1971 Immigration Act which was going to be the 'end of large scale immigration to the UK', that [U]nothing[/U] can be assumed with the Home Office!
Here's some background reading which shows that the claim 'but we've always been a country of immigrants' is absolute tosh!
http://webarchive.nationalarchives.gov.uk/20160105160709/http://www.ons.gov.uk/ons/dcp171776_346219.pdf
"The world is still a weird place, despite my efforts to make clear and perfect sense of it".
Dr. Hunter S Thompson
