Argue the toss
Definition 1 of 1
Pro Tip 1/3British Idiom
Mainly used in the UK, so understanding local context is important when using it. 
When I moved to London, I had to learn phrases like 'argue the toss' to blend in.
Pro Tip 2/3Pointlessness
The phrase often implies that the argument is pointless or the outcome won't change. 
He's wasting his breath trying to argue the toss with the referee's final decision.
Pro Tip 3/3Negative Connotation
Using this phrase can imply a negative view of someone's insistence on arguing. 
She's always ready to argue the toss, even over clear-cut rules.