Switching characters in UVHM?

I have a maxed out level 50 character for each class. I am about to jump into UVHM. Is there anyway to switch character mid game without starting all over?

Say for example I want to do the first few quests as Zer0, then the next few quests as Maya, then the next few as Axton. Is there any way to do this without starting all over for each character?