Well, of course. Brexit was a massive own goal at the hands of regressive nationalism.
As a European citizen who grew up in the UK, I took the Brexit vote very personally. Not being able to legally live in the place you used to call home is very hard (although I'm fully aware that many people around the world have experienced a much harsher version of this story). I would very strongly welcome a reversal.
Britain's current Labour Party is next to useless, unfortunately, choosing centrist politics over offering a real alternative. I don't know that they'd be bold enough to make this correction under their current leadership. But maybe? #Democracy