National has made a leadership switch four months out from an election, ousting unpopular leader Simon Bridges and replacing him with untested agriculture spokesman Todd Muller.
Mr Muller was victorious in a leadership ballot at an emergency caucus meeting today.
Nikki Kaye has been elected deputy, replacing Paula Bennett.
Mr Bridges' leadership appeared increasingly untenable after two horror polls were published this week with National at decade-long lows.
The Tauranga MP made a series of tone-deaf political interventions as New Zealand battled with Covid-19, contrasting poorly with the leadership of Prime Minister Jacinda Ardern.
While Mr Bridges maintained confidence in his leadership throughout, a majority of his partyroom saw otherwise, installing Mr Muller.
Mr Muller didn't mount a public campaign but laid out the premise for his challenge in an email to the 55 National MPs announcing his candidacy.
"Labour has failed to deliver on every measure it has set for itself in Government. This will not change and the consequences of it being re-elected at this time will be catastrophic for two generations," he wrote.
"Our communities and our economy are at stake. It is essential National wins this election.
"I share the view of a majority of colleagues that this is not possible under the current leadership.
"I believe I am best placed to earn the trust of New Zealanders by September 19."
In making the switch, National are making a similar bet to Labour during their 2017 campaign.
Then, Ms Ardern replaced her hapless predecessor Andrew Little just seven weeks before the poll, producing a double-digit poll bump and providing a basis to form a coaltion government.
After the vote, Mr Muller moved quickly to present a united front despite the week of tumult.
"There is no Team Todd, there is no Team Nikki, or anyone else - there is only Team National," Mr Muller said in a statement.
"National has always been a coalition of city and country, business and community, conservatives and liberals - National is the party for all New Zealanders.
"New Zealanders need a National Government with the experience and management skills to get our country through the worst crisis since the end of the Second World War.
"My focus as leader is our country's economic recovery and the strengthening of every community throughout New Zealand."
Mr Muller faces a hard ask to win office from Ms Ardern, with Labour riding high at 59 per cent - their best-ever result - in the most recent 1 NEWS poll, compared to National's 29 per cent.