Making rigorous demands (8)
I believe the answer is:
exacting
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">making rigorous demands</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for exacting that I've seen before include "Demanding much" , "Difficult and onerous" , "Requiring great effort - sounds precise" , "Not easily satisfied" , "Arduous and demanding" .)