Checking for right to work has been legally required for over a decade. Checks in the formal economy are now routine. Can sometimes be a nuisance, like for my friend who doesn't have a passport and his driving license was issued before those went photographic.
Someone who is prepared to pay people smugglers to help them cross a border illegally may not choose to restrict themselves to working in "the formal economy".
"Illegal working and streams of taxis - BBC gains rare access inside asylum hotels"
