1925 London County Council election
... that, following the 1925 London County Council election, the Labour Party became the official opposition on the council for the first time?
... that, following the <b id="mwBWQ"><a href="./1925_London_County_Council_election" id="mwBWU" rel="mw:WikiLink" title="1925 London County Council election">1925 London County Council election</a></b>, the <a href="./Labour_Party_(UK)" id="mwBWY" rel="mw:WikiLink" title="Labour Party (UK)">Labour Party</a> became the official opposition on the council for the first time?