Don't want Husband's father to visit

So a very long story short but I do not care for my husband's biological father. I didn't even meet him until after we were engaged and within the first hour I was very uncomfortable and that hasn't changed. He isn't a responsible man and he isn't very clean.

He is always nice to me and I would never be intentionally rude to him. I am due any day now and I don't know how to tell my husband I don't want his bio dad or his girlfriend coming to see us. They are both pretty heavy smokers and have not refrained from smoking around me while I have been pregnant so I don't expect them to around our son. They smell like smoke pretty much all the time.

They are literally the only two people I do not want around anytime soon and I have thought about it and my husband probably wouldn't even mention to his dad that I am in labor but I know as soon as my brother in law knows their dad will know.

Any suggestions or insight?

Edit: I am not uncomfortable with any others from his family visiting. Love my mother in law and my husband's step father! We spend a lot of time at family events on both sides. His bio dad wasn't around for several years and he is back now but we hardly see him anyways. A birth is a big event though.