Mutually hostile jerks get grand awards (2,7,5)
I believe the answer is:
at daggers drawn
'mutually hostile' is the definition.
(I've seen this before)
'jerks get grand awards' is the wordplay.
'jerks' is an anagram indicator (I've seen 'jerk' mean this).
'get'+'grand'+'awards'='getgrandawards'
'getgrandawards' is an anagram of 'AT DAGGERS DRAWN'.
(Other definitions for at daggers drawn that I've seen before include "show of open hostility" , "in hostile state" , "In state of hostility" , "Mutually hostile" , "prepared to fight" .)