So who is the new Labour leader?
David Cunliffe, 49, was born in Te Aroha, the son of an Anglican minister and a nurse.
He now lives in the wealthy Auckland suburb of Herne Bay - outside of his New Lynn electorate - but he grew up in Te Kuiti and Pleasant Point, near Timaru.
He followed his father into the Labour Party and though he says he does not often attend church, he remains a committed Christian.
Mr Cunliffe studied politics at Otago University, where he was also a member of the debating team. It was there that he met his wife Karen Price, an environmental lawyer, with whom he has two sons.
He then moved to Harvard University as a Fulbright Scholar and Kennedy Memorial Fellow and graduated with a masters in public administration.
After Harvard he worked as a diplomat, an economist and as a business strategist for Boston Consulting Group.
He was seen as one of a new wave of Labour MPs who are wealthy, highly educated and comfortable with business groups as well as unions.
Mr Cunliffe was first elected in the Titirangi electorate seat, which later became New Lynn, in 1999. He has held the New Lynn seat since 2002.
He was a successful minister in Helen Clark's Government, in which he held the health and IT portfolios. As IT Minister, he earned praise for unbundling Telecom's local loop monopoly. After Labour was defeated in 2008, he rose to number 3 on the party list and was appointed finance spokesman.
When Phil Goff stood down as leader after defeat in the 2011 general election, Mr Cunliffe ran for the leadership but lost to David Shearer.
He was demoted to the backbenches in February after he refused to rule out a challenge for Mr Shearer's position at Labour's annual conference in November.
After Mr Shearer resigned on August 22, Mr Cunliffe made his second bid for the leadership.