Unions often will not allow termination via the contract. If the company doesn't like someone they need to take it up with the union. If the union likes the "bad person", then you are probably stuck as everyone else in the union will walk off the job if you try to fire that person. If the union hates someone that you like, the union can refuse membership to that person (I've never heard of this happening, though unions often do refuse membership to someone unknown to you who might or might not be good)

Of course each union contract is different, but it is very common for it to be impossible to fire a bad union employee as the union won't let you. (and in fact the union often won't even let you collect data that shows how bad they are).

None of the above applies to every case. If you don't show up for work, then you are out: no union will defend someone who can't even be bothered to show up. If you do something illegal you are out. These days sexual harassment is something the union won't defend (in the past that wasn't true) and so you will be fired for that. Each contract has different fine print.

After Peter's reply, I looked into it a bit. This page has some useful information on it

https://employment.findlaw.com/wages-and-benefits/labor-stri...