This isn’t new to the UK. Scotland has seen a number of AV by-elections this month alone. And, lo and behold, a number of centre-left parties stood, and far from splitting the vote – centre-left parties won in both instances. Northern Ireland, which also uses PR for its Assembly, like Scotland uses AV for its by-elections.
Article source: http://www.huffingtonpost.co.uk/josiah-mortimer/zac-goldsmith-richmond-by-election_b_12685636.html?utm_hp_ref=uk-politics&ir=UK+Politics