Complete freedom to act as one wishes (5,7)
I believe the answer is:
carte blanche
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">complete freedom to act as one wishes</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 carte blanche that I've seen before include "free rein" , "Full discretionary power" , "total freedom" , "Complete discretion" , "Unrestricted authority" .)