As I'm in charge of 10 Polish workers, tomorrow I shall randomly (don't want to appear to be prejudice) pick one of them out and make their day as miserable as possible.
I don't understand - you hire Polish workers, so you must benefit from that (unless your management and managers are silly enough to hire them and they lose money because hiring them). Perhaps you should make your point and put your money where your mouth is - and fire them all and hire only native British citizens? Now you feed the Polish workers and their Polish families instead of British workers and you still complain about that - why is that? You are the manager, you set the rules, or not?