Judith Collins, Gerry Brownlee 'can win' - Dame Jenny Shipley

National's first female leader and the country's first female prime minister Dame Jenny Shipley says Judith Collins becoming leader is significant in New Zealand politics.

"She may well be the fourth woman prime minister in New Zealand. I would be delighted if that were the case as well."

Dame Jenny told Morning Report even though the past few weeks were dramatic for National, "our current prime minister was in exactly the same position and has gone on to be successful".

"Judith is a very experienced politician. She's been an outstanding minister in multiple portfolios, she's always across the details, she's extremely bright ... she doesn't take prisoners and I mean that in a constructive way. She's not a person who is unkind, she's a person who will look at the facts and then make a judgement."

She said Collins and Prime Minister Jacinda Ardern were both capable leaders.

"Gerry [Brownlee] is a very good manager," she said.

She said the deputy needed to back the leader and support the caucus.

"Gerry is overqualified. I've worked with Gerry in Canterbury when we were in deep and complex trouble post the earthquake ... he is a solid leader.

"Of course I think they can win."

National has had three leaders so far this year, and five since Ardern became prime minister in 2017.

'Judith now has to pick up the pieces'

ACT Party leader David Seymour hasn't spoken to Judith Collins since her win last night.

"The National Party has had quite a tumultuous time."

He said a lot of people have thought of waking up and sending an email and leaving everyone else to it. "Todd's done that and Judith now has to pick up the pieces."

There was a need to get smart about public health, he told First Up.

"So far we've benefitted more from good luck than good management."

Collins will be the fifth National leader that Seymour will have worked with. Yesterday, Seymour said he hoped it wouldn't be six by the end of the election.

"I've worked with Gerry as well and I've found him one of the most genuine people in Parliament. Judith and I have been on the Finance and Expenditure Committee together for what seems like years now.

"The issue is not so much the people, the issue is the future of the country."

No 'nasty politics' - Jim Bolger

Former National Party prime minister Jim Bolger said Collins and Brownlee were a predictable and right choice.

Bolger told Morning Report the pair would need a specific policy approach to address the economic issues brought about by Covid-19.

"We have to decide whether we follow traditional economics and we pay that off over the next 20 years by austerity politics or we say 'we owe it to nobody, the Reserve Bank has created it' and we write most of it off.

"We also need to have from Labour and National clear policies on when they are going to address the debt and social inequality within New Zealand."

And he said they needed to keep away from nasty politics.

"[The public] want politics that address their bread and butter issues, job and income, and a future for their children. They don't want any smart, nasty politics, in my view."

Voters speak

Pensioner Bob Tait from the Auckland Central electorate said he was not a fan of Collins.

"She's capable and probably the National Party's best hope," he said.

"What chance have they got of coming back after such a severe setback? But she's very ambitious."

He said poll numbers would marginally go up for National but not enough to win.

Auckland Central voter Roger Reynolds said: "This leadership is said to be a poisoned chalice. Judith Collins might be the only member of the National caucus who is immune to the poison."

He said Collins coming in would appeal to the existing party base but wouldn't attract new voters.