Key says he would vote for his deputy prime minister, Bill English, if he put his name forward for leader
John Key, the New Zealand prime minister and leader of the National party, has resigned in a decision that has taken the country by surprise.
Key held a media conference in Wellington at 12.45pm local time, after informing the cabinet of his decision.
His resignation would be effective 12 December, when National MPs would meet to select a new leader.
Key said he would vote for his deputy prime minister, Bill English, if he put his name forward. English briefly led the party to its worst-ever electoral defeat in the 2002 election, but has since served as a successful finance minister.
Key is widely regarded as one of the most popular prime ministers in New Zealands history. He was first elected in 2008, and recently marked his 10-year anniversary as leader of the National party.
He said stepping down was the hardest decision he had ever had to make, but there was no way he could have served a full fourth term.
This felt like the right time to go, he told reporters. Sometimes youve got to make hard decisions to make right decisions, he said, adding it was an opportunity to refresh the National partys leadership of the country for a fourth term.
I think one of the reasons governments fail at that fourth-term hurdle is leaders dont want to leave, everyone says Ive seen this before. This is the chance to demonstrate newness about us.
He said he had a pretty long discussion about standing for a fourth term with his wife, Bronagh Key. I dont feel comfortable looking down the barrel of the camera and not being honest … On a family basis, I dont think I could commit much longer than the next election.
He denied that Bronagh Key had given him an ultimatum, but said his leadership had come at a cost to his family. Its been a decade of a lot of long, lonely nights for her and its the right time for me to come home.
His children, Max and Stephie, had suffered an extraordinary level of intrusion along with the opportunities that came with being New Zealands first family.
In the past year, Key has had to answer to questions about his sons burgeoning career as a DJ and social media personality. Spending more time with his family was a major factor in his decision to stand down, he said.
Key said he believed the mark of a good prime minister was one who led the country in better shape than they found it.
Over time others will judge whether Ive done that. All I can say is I gave it everything I had. I have left nothing in the tank.
He said he considered his economic management of the country as a mark of success, even though New Zealand had weathered some crises during his government, including the Canterbury earthquake and the Pike River mining disaster. Very few countries are in the financial position were in.
One of his regrets was not getting the Trans-Pacific Partnership over the line, as well as his failed bid to change the flag.
Key said he would remain in parliament long enough to avoid a byelection, but would step down as an MP before the next election. He said he stood down hoping and believing New Zealand had been well served by the government I led.
English, who has Keys backing to replace him, praised the prime ministers intelligence, optimism and integrity and said he would be judged by history as one of New Zealands greatest leaders. He said the National caucus would now consider the implications of the prime ministers decision, and that Key left behind a united team with plenty of talent.
He did not indicate whether he would stand for the leadership.
The leader of the Labour party, Andrew Little, and the Green party co-leader, Metiria Turei, both wished Key well for the future on Twitter.
ACT New Zealand leader David Seymour congratulated Key on the noble way he has bowed out.
Australias opposition leader, Bill Shorten, said Key had been a good friend to Australia and wished him well.
The New Zealand dollar fell more than a quarter of a cent after the announcement.