go at one another tooth and nail
To fight, battle, or compete against one another with great ferocity, vigor, and intensity. The incumbent president and his rival went at one another tooth and nail in the televised debate last night. The rioters and police have been going at one another tooth and nail all night long.
go at one another tooth and nail
Fig. to fight one another like animals. (One another can also be each other.) The man and his wife went at one another tooth and nail. The children would go at one another tooth and nail almost every evening.