Boss: I've decided to pay you shit wages and expect you to work nightmare hours.
Union: We've all banded together and would collectively like to tell you that we prefer better wages and more reasonable hours, or else we will strike.
Boss: I've decided you can't do that, or else.
Union: Yes, or else, indeed. That's the core concept here.
Call his fuckin' bluff, or else you don't really have a union at all.