Ruthless competition (3,3,3)
I believe the answer is:
dog eat dog
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ruthless competition</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dog eat dog that I've seen before include "Condition of savage self-interest" , "Ruthless (canine cannibalism?)" , "Savagely competitive" , "aggressive" , "fierce competition" .)