Wikipedia - NZLP
Members of the Labour Caucus in the New Zealand Labour Party take a confidence vote on the leadership of the party's parliamentarians.
This is usually a routine event during the middle of the election term, but this time party leader David Shearer will need 60 percent of the Caucus vote. If he fails to get sufficient backing from the party hierarchy, it will mean a new leadership contest.
Since 2008 the Labour Party has suffered faction fights and splits, and it failed to defeat the National Party in the last election. The confidence vote is regarded as an indicator of Shearer's ability to restore unity in the party ranks.