Free rein (5,7)
I believe the answer is:
carte blanche
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">free rein</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for carte blanche that I've seen before include "Free hand" , "Complete discretion" , "Complete freedom to act as one wishes" , "Unrestricted authority" , "Complete freedom of action" .)