How did that turn out?
Some within the National Party will hope history repeats today, with Simon Bridges facing a new and untested rival, Todd Muller, with an election just months away.
Ms Ardern was at least a known quantity; she had been touted as a possible party leader for years and had served as deputy leader.
Mr Muller — 16th in the party rankings but sinking like a stone if this audacious gamble fails — is well-known in rural and business circles but is little-known to the general public.
The star power for his tilt at the leadership comes from his proposed deputy, Nikki Kaye, whose return to politics following serious illness is a compelling story.
On the surface, the catalyst for this seemingly precipitate coup attempt was a dire opinion poll which showed National 12% down and seemingly staring political oblivion in the face.
That would be unlikely; no-one attempts to roll the leader in the space of 48 hours.
It takes weeks of careful planning and backroom conversations to establish if there is appetite in the caucus room for a leadership vote.
Few MPs move to unseat their chief unless they are very sure of their numbers — failure is a sure ticket to political obscurity.
Mr Muller says he has the numbers, so too does Mr Bridges ... both cannot be correct.
Beating a prime minister with historic personal preference poll ratings at a time of national crisis was always going to be difficult. This leadership challenge will make things much harder.
Did National have to put itself through this turmoil?
In February the One News Colmar Brunton poll had the party at 46% and, with Act holding its coat-tails, a realistic hope of winning this September’s election.
Ms Ardern has obliterated that advantage in the latest polls but she, like many leaders across the globe, has received a poll boost on the back of their national efforts to stem Covid-19.
Some of that gain would have evaporated as Level 3 and 4 became a memory, and with unemployment rising and a recession biting more might have been lost in the face of a determined Opposition campaign.
While Mr Bridges has made the occasional ill-judged speech in recent weeks and has a personal style which grates with some voters, he has had to fight an uphill battle to give National visibility at a time when Ms Ardern was holding widely watched daily televised press conferences.
Also, while sometimes at odds with the sentiment of a national struggle against the pandemic disease, Mr Bridges has tried to provide meaningful opposition at a time when Parliament was in recess.
The odds have been stacked against Mr Bridges for weeks now, but he is not going down without a fight.
By calling a leadership vote today he has forced Mr Muller to up his timid opening bet of an anonymous call for a vote of no confidence into an all-in bet on his — or Mr Bridges’ — political future.
How will that turn out?
Whoever emerges beaming to take questions from the Press Gallery, they will be at the head of a team demonstrably riven by factions — not just those who backed Mr Muller and Ms Kaye or Mr Bridges, but those who prefer other possible leaders who have kept their powder dry and opted not to enter this fray.
The successful MP will have to convince voters National is united and ready to govern, in the face of compelling evidence to the contrary.
What was already a tough job this September for National is now much harder.
