Ardern says no longer has 'enough in the tank' to seek PM re-election

The announcement to step down by New Zealand's Prime Minister Jacinda Ardern was a shock to her colleagues and many in the nation.

Addressing the Labour Party's annual retreat where she announced the general election would be held on Oct 14 this year, she then dropped her bombshell, saying, "I will be stepping down as your prime minister next month."

Choking back tears, Ardern, 42, said she no longer had the energy to seek re-election.

"I know what this job takes. And I know that I no longer have enough in the tank to do it justice," she said.

"I would be doing a disservice to continue."

The Labour Party will vote on a new leader on Jan 22.

With her fiance, Clarke Gayford, sitting a few meters from her and her 4-year-old daughter Neve, Ardern said: "Neve, mum is looking forward to being there when you start school this year." And to Gayford, she said: "Let's finally get married."

Frontrunners to succeed Ardern include Education Minister Chris Hipkins, Foreign Minister Nanaia Mahuta and Immigration Minister Michael Wood.

Ardern is expected to step down as prime minister on Feb 7 and resign her seat in April.

Internationally Ardern was greatly admired as a leader, but domestically her popularity had started to fall.

Ardern became the world's youngest female head of government when, at 37, she was elected prime minister in 2017.

She has led the country through the COVID-19 pandemic, the terror attack on two mosques in Christchurch, and the White Island volcanic eruption.

Over the past year, Ardern has faced an increase in threats from conspiracy theorist and anti-vaccine groups infuriated by the country's vaccine mandates and COVID-19 lockdowns.

Recent polling shows Ardern and the Labour Party slightly behind the opposition New Zealand National Party.

Ardern said her decline in the polls was not behind the decision to leave.

Australia's Labor Prime Minister Anthony Albanese said Ardern had shown the world "how to lead with intellect and strength".

University of Auckland political analyst Lara Greaves said polls showed that if an election were held today, Labour would likely lose.

"A lot of the erosion of Ardern's popularity, and Labour's popularity, has been around not being really able to fight for the working class or the middle class ... or just really make their day-to-day lives easier in terms of their economic well-being and their ability to make ends meet," Greaves told the Australian Broadcasting Corporation.

She said Ardern's exit is likely much more of a surprise on the world stage than domestically, and cited a "misalignment" between "public perceptions of Ardern in New Zealand compared to what you see overseas".

"We really saw Arden's Labour government come up against these realities of having to suddenly act like there had been no COVID crisis … to try to really have a policy platform and make transformational change, and they just really weren't able to meet a lot of that," Greaves said.

New Zealand now has the highest homelessness rate per capita in the OECD. The cost of living has risen sharply.

The New Zealand Human Rights Commission is now looking into the country's housing crisis which has grown worse under Labour.

Grant Duncan, an associate professor at New Zealand's Massey University, told the media that Ardern attracted a lot of positive international attention after handling crises such as the pandemic, the Christchurch mosques terror attack and the deadly volcanic eruption.

"But domestically, she's become, unfortunately, somewhat of a polarizing figure, because of the consequences of the pandemic and the current economic problems," Duncan said. There had been "a question about whether the Labour Party will be successful at the next election. They've not been doing very well on the polls here."