argue the toss
US /ˈɑːrɡju ðə tɒs/
UK /ˈɑːrɡju ðə tɒs/
1.
to dispute a decision or choice that has already been made, especially when it is too late to change it
:
•
It's no use arguing the toss now, the deadline has passed.
•
The manager made his choice, so don't even try to argue the toss.