It's too easy to be goodies and baddies on this. Not all migrants are what they seem. Some are potentially dodgy but, crucially, some are the lucky ones to escape from their countries. The richer, better educated ones which their home countries need in order to rebuild and positively develop them. (I read an article on this by Goodhart).
So rather than just let everyone pour into UK, draw up a plan to educate and support people and get them back to their own countries with more to offer their countrymen. For those escaping war zones he postulated time limited asylum enabling people to return home after the immediate problem (whatever it was) has passed. Meanwhile UK govt to encourage our professional bodies to interact directly with these countries to help them to develop to higher standards rather than just sink lower as they've lost their brightest and best hopes. I hope I've conveyed that right. It seemed an interesting idea.
Old sayings with a theme 2 ( continuing *nanna8*'s thread)