Judith Collins' election 'extraordinary outcome', promises 'bad news for Winston Peters' - political commentator

New National leader Judith Collins is a "totally different" politician to those previously in the party's top spot and could spell bad news for New Zealand First, a political commentator says.

After Todd Muller's bombshell resignation on Tuesday morning, Collins was given the nod of approval to lead the party later that evening, promising to take on the current Government and give Kiwis a choice at this year's election.

Collins, a lawyer who first entered Parliament in 2002 and held several ministerial roles in the Key and English Governments, has long wanted to be leader, putting herself up twice before for the role.

Dr Bryce Edwards, a political analyst from Victoria University, says Collins' rise on Tuesday was an "extraordinary outcome from what has been an extraordinary year in politics". 

"She is someone who has been in the wings waiting for her chance to lead her party and she has finally got it. She has been tenacious, she has been holding on, she has finally got it," he told Newshub.

He said she has been wanting the role since serving under Key.

Noting that National has now had four leaders in this one parliamentary term, Dr Edwards called Collins a "unique politician" who stood out from previous leaders. He said they "lacked a bit of colour".

"There is no one else like Judith Collins," he said.

"Where she has excelled, I think, at least on the right, is as a conviction politician. She is someone who is differentiated from the more centrist and bland leaders who have actually led National in recent years.

"She stands up for what she believes in and I think that is something that is quite different from a lot of other leaders. A lot of the public might disagree with what she believes in but I think they might respect her authenticity and that will be one of the big selling points of her leadership."

Dr Edwards said that other leaders, like John Key, took National towards the centre of the political spectrum.

"Judith Collins will at least not disappoint those on the right and her own base. She will energise National Party activists and those on the right who want a more true blue National Party."

One of her first challenges will be dealing with a National Party that appears to be fractured upon factional lines, Dr Edwards said. 

"Judith Collins may have to face trying to unite the party and stare down dissidence and people who aren't really her friends and I think she does have a lot of people who aren't her friends in caucus.

"There is a lot that she is going to have to do. But, of course, her colleagues are going to be very driven by the one outcome, which is the party vote in nine weeks time. They will get behind her if they think it is going to save their own jobs."

He said Collins' election as leader was a "disruption" to the election campaign and "bad news for Winston Peters". 

"I think that New Zealand First are going to be damaged by this. Any chances of Winston Peters and New Zealand First coming back with a populist campaign over the next nine weeks is really in doubt now. Collins is going to go after that populist vote. She is going to get that more conservative vote that Peters might have hoped for."

Dr Edwards suggested Collins may be challenged by what is seen as her connections to dirty politics and she will have to prove her honesty and integrity to New Zealanders.

He said Kiwis are turned off by toxic politics.