OK ….UK gov built an economy based on services and consumer capitalism . Cheap food , hospitality, cheap imported goods , distribution centres , all of which needed an increased labour force , cheap cash . Actively recruit overseas labour to grow economy . Pre Brexit .
This is the disaster at the heart of GB's economic failure: gdp growth by population boosting while wages and gdp per capita stagnate (a pre-Bexit phenomenon). Reversing it first and foremost requires ending the source of cheap labour, which voters have figured out.