Division into opposing factions (6)
I believe the answer is:
schism
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">division into opposing factions</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 schism that I've seen before include "(Ecclesiastical) division" , "Split (usually in church)" , "Dividing of group into opposing factions" , "Friction or division in church organisation" , "Deep division" .)