Tory rival
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tory rival</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 whig that I've seen before include "Former 14 Down" , "Old-style politician" , "Seventeenth century politician" , "Member of a former reforming party" , "Former political party member" .)