Three conservative legislators in New Zealand have said they want to replace John Key as prime minister.
The contenders are deputy prime minister Bill English, health minister Jonathan Coleman and corrections minister Judith Collins. Several other National Party figures said they have not ruled out entering the race.
In New Zealand, the prime minister is chosen by the governing party's top legislators, who make up the caucus. The caucus is expected to take a vote at a meeting on December 12.
The new prime minister will have about 10 months to run the country before a general election next year.
Mr Key had been a popular leader for eight years and was widely expected to contest a fourth straight election next year before he shocked the nation on Monday by announcing his resignation.
He has endorsed Mr English, who is also the finance minister. The 54-year-old led the National Party 15 years ago for two years, but suffered a big defeat in the 2002 election which was won by the rival Labour Party led by Helen Clark.
Supporters say Mr English has managed the economy exceptionally well under Mr Key and would make a steady hand as leader. Critics say he is dull and lacks the charisma needed for the top job.
Under Mr English, New Zealand has been enjoying relatively robust annual GDP growth of over 3% and the unemployment rate has fallen below 5%. He has also managed to return small surpluses on the government's books over the past couple of years.
Mr English said he would deliver tax cuts and spread the country's wealth to where it is needed. He added that he has gained wisdom and experience since last running the party.
"I was 39 years old then, with six children under 13," he said. "So if nothing else, I've got the opportunity to focus much more on the job now than was the case then."
Mr Coleman, 50, is known for being ambitious but his decision to run came as a surprise to many. He said he has attributes that go beyond his time in parliament running the difficult health portfolio.
"I was not a career politician so I've been a doctor," he said. "I live my life in the community. My kids go to state primary schools. So I think I have a deep connection with the concerns of ordinary New Zealanders."
He said there was an appetite for change in the party and he liked where he was positioned in the race.
Ms Collins, 57, is known as tough, plain spoken and something of a maverick. In 2014, when she was justice minister, she was forced to resign her portfolio three weeks before the general election due to her ties with a controversial blogger. She remained as a member of parliament.
About a year ago she returned to the inner circle of the cabinet, taking on the police and corrections portfolios.
"One of the things that you learn in life is that you learn from things that go wrong," she said, adding that she stayed because she believed she was still adding value.
"We're going to go into the toughest campaign ever that we have fought," she said. "And I know that we need to win, and the only way we can do that is if we have some of the toughest people running."