What happens to parties that change PM mid-term

As Prime Minister Christopher Luxon prepares to face the National Party caucus this morning, we look at the fate of parties who change the person at the top between elections.

Some Prime Ministers resign by choice – others are forced out – but the country’s recent political history shows many administrations fail to recover from swapping leaders mid-term.

In 2023 Jacinda Ardern’s surprise resignation would see Labour lose power later that year. In 2016 John Key’s shock departure would later lead to National losing power.

And in the 1980s the fourth Labour Government was severely punished by voters at the 1990 election after cycling through three Prime Ministers in just 13 months.

Chris Hipkins replaced Jacinda Ardern as Prime Minister after she resigned, declaring she "no longer had enough in the tank" to do the job justice.

"To Neve, mum is looking forward to being there when you start school next year. To Clarke, let's finally get married," Ardern said in a decision that shocked her colleagues at a Labour Party retreat in Hawke’s Bay.

Hipkins has remained as Labour leader since.

If Ardern’s resignation was a surprise, John Key’s decision to step aside came as a political bombshell. Key had been a vastly popular Prime Minister and appeared on track to comfortably win a third term in 2017.

However he walked away from the top job at the end of 2016, saying his political success had come at the cost of spending time with his family.

“For my wife Bronagh, there have been many nights and weekends spent alone, many occasions that were important to her that I simply could not attend,” Key said on the day he quit.

“My daughter Stephie and my son Max have transitioned from teenagers to young adults while coping with an extraordinary level of intrusion and pressure because of their father’s job.”

Bill English was elected to the top job unopposed. He would go on to lose the 2017 general election – despite National comfortably wining the party vote – as Winston Peters decided to go with Jacinda Ardern’s Labour Party.

Jenny Shipley became the country’s first Prime Minister by rolling Jim Bolger in an internal caucus challenge.

But unlike Ardern and Key, Bolger had no intention of resigning until he returned from an overseas trip and was confronted with the fact he no longer had the numbers.

Bolger would go down in history as the final PM to serve under the First Past the Post electoral system.

Shipley was 45-years-old when she ascended to Prime Minister but led National to an election defeat by Labour’s Helen Clark in 1999.

Mike Moore replaced Geoffrey Palmer but his tenure would only last 59 days.

The fourth Labour Government was facing a heavy election defeat and turned to Moore for leadership, after he convinced the caucus that he would help save more seats than if Palmer continued as leader.

Palmer initially rebuffed Moore’s challenge, declaring on September 3 1990: “I want to make it absolutely clear to every New Zealander that I am not quitting.”

However within a day he had decided to resign, just eight weeks from the general election.

David Lange resigned dramatically as Prime Minister as he struggled with health problems and losing control of a divided Cabinet. His successor, Geoffrey Palmer, described his ascension as a “hospital pass”.

Lange had spent five years as the country’s 32nd Prime Minister after leading Labour to victory in 1984.

But by 1989 Palmer inherited a Labour Party divided by the pain of 'Rogernomics’ (Finance Minister Roger Douglas’ neo-liberal economics) which was exacerbated by the 1987 worldwide share market crash.

Norman Kirk had died in office from heart failure on August 31, 1974. Deputy Prime Minister Hugh Watt served briefly as the acting prime minister for several days, until the Labour caucus elected Bill Rowling as the country’s new leader.

Keith Holyoake resigned as Prime Minister of New Zealand after 12 years in office, handing the premiership to his deputy, Jack Marshall. National would go on to lose the November 1972 election to Norman Kirk's Labour.