Insider's look: The rise of Jacinda Ardern, and dealing with Winston

Former Labour MP Annette King has criticised the way the Labour chooses its leader in a new authorised biography, saying it was likely Jacinda Ardern would not have got the top job if she had had to go through the usual vote of members, MPs and unions.

A new biography of Annette King provides new details and an insider's account of significant periods in Labour's history - from Rogernomics, through several leadership changes to King's role in the coalition talks with NZ First after the 2017 election.

As well as King's own personal and political life, the book provides new details about the leadership changes from Helen Clark to Phil Goff, then to David Shearer, David Cunliffe, Andrew Little and the days of Little's handover to Jacinda Ardern.

King was also an insider in the coalition brokering between Labour and NZ First after the 2017 election.

She had helped advise Ardern on what it was like dealing with Peters: "People say worry about Winston. I say don't worry about Winston. I worked with him and we were in government with him and he did what he said he was going to do."

Read an extract from the new book: Annette King – The Authorised Biography

King says she does not agree with the process by which the Labour Party chooses its leader, by allowing members and the unions to have a vote as well as MPs.

That 2012 change meant both David Cunliffe and Andrew Little were elected leader, despite Grant Robertson having far stronger support in caucus.

Ardern was elected by the caucus alone, because Labour's rules allow that to happen if the leadership comes up within three months of an election.

King says she does not believe Ardern would have made it into that job had it been otherwise, or that she could have beaten Cunliffe.

Asked about that by the NZ Herald, King said she did not know if the rules would ever change back, but there had been some talk about it.

"I think Jacinda becoming the leader is a really good example of it. Jacinda rose out of the caucus, caucus voted for her and what a good choice they made.

"The caucus knows the caucus. They know how people work, they know their strengths and weaknesses. They know whether they can work as a team with them. For me, the caucus ought to choose the leader.

"The party can have as much say as they like developing policies and choosing candidates to represent them on the hustings. But I don't believe the membership have the same knowledge of a leader as the caucus."

King pointed to Cunliffe's leadership as an example of the error in the method. "David Cunliffe did not have the support of caucus. That was because the caucus did not see him as the leader, they did not see him being able to lead us in a positive way. I don't resile from what I said [in the book]. Those were the facts as I saw them in the caucus."

In the book, King said Little did earn caucus respect, but made it clear she was no fan of Cunliffe, saying he had struggled to connect with other MPs in every caucus he was in.

The book also gives new details about the rise of Ardern to be leader in the lead-up to the 2017 election.

Little reveals he spoke to King prior to his decision to step down and hand over to Ardern, after a string of bad polls. While King had not told him to go she had said it was a risk to stay on: "Equally it's a risk to step aside and let Jacinda in, but actually the indications are that Jacinda could pull it off," King told him.

King also talks about her own close friendship with Ardern, including admitting she had not initially thought Ardern's partner Clarke Gayford was the right man for Ardern.

"She was really keen to be in a stable relationship and I have to say I wasn't sure Clarke [Gayford] was the right person to start with. A bit like your parents who look them over and wonder whether this one is right, and I remember saying to Ray 'I don't know whether he's the right one for Jacinda.' I was totally wrong."

King was also responsible for the initial development of the KiwiBuild policy, saying when it was devised in 2012 they had considered setting the target even higher than the 100,000 that was in the final policy.

She says the initial policy was for 50,000 homes over 10 years, but it was shifted up to 100,000 and they had considered going even higher "because if you look at what we were building in the '70s we could easily have cranked up to 100,000 homes in 10 years." She still believed the party could easily reach the target, despite the failure to meet the short term goals.

On Darren Hughes:

The book includes an interview with Darren Hughes who boarded at King's house and quit Parliament in 2011 after a complaint to Police by an 18-year-old male who went back to King's house with Hughes late one night. No charges were brought, but Hughes quit and moved to the UK.

Hughes has not spoken publicly about that time since, but says in the book he had known it would be used as a "battering ram" and wanted to spare his party: "I still feel conflicted about that. I think as a matter of justice there should be proper process and you shouldn't just resign.

"But then I had a moment of absolute clarity in a messed-up situation. I realised I could always get another job but I couldn't get another personality .... I realised if I stuck it out, there was a risk of paranoia, of bitterness, a risk of anger - why is this happening to me? - I have seen lots of people like that ... and now all these years later I am the person I was."

King refers to that time as "the Troubles" and says the coverage and behaviour of some media had angered her.

Hughes was close to Ardern and both King and Ardern said that time and the relationship was partly why their own friendship developed.

On David Cunliffe: "a disastrous reign" and David Shearer:

The book has a blunt - and sometimes brutal - appraisal of former leader David Cunliffe by King and former leader Phil Goff. Goff reveals when he was made leader after Helen Clark's resignation, Cunliffe had lobbied for it himself and then proposed a co-deputy model to allow him to be a deputy alongside King. Goff had refused.

Cunliffe led Labour to a 24.7 per cent result in 2014 and King said the caucus after that, when Cunliffe was still considering seeking re-selection as leader, was one of the most brutal she had been at, likening it to those at the end of the Rogernomics years. "It was made clear to David the caucus would not accept him to continue."

King was also critical of Cunliffe's actions when David Shearer was leading, saying he and his supporters were clearly seeking to undermine Shearer at the Labour Party conference in 2012 despite denying it at the time.

That was the conference at which Labour voted to change the way they voted for the leader to allow members and unions to have a vote - and to allow a leader to be overthrown by just 40 per cent of caucus rather than the usual majority.

King, who was also Shearer's deputy, says no Labour leader was treated as badly as Shearer was at that conference.

The book also reveals it was King and Goff who went to Shearer to advise him of a no-confidence letter being prepared by other MPs. Goff said: "Both of us fronted up and told David we've done the numbers in caucus mate, and they're going to go for a spill and you won't win it and so you can stare them down but they're going to vote you down."

King had a different take on events, saying she believed Shearer should have "done a Helen Clark" and stared down those who were saying he should go.

That was a reference to 1996, when King and Goff were among those who went to Clark's office to say she should step down as leader because the party was polling at about 16 per cent and Clark had hit two per cent as preferred Prime Minister.

"[Shearer] rolled over. It became in the end that people went in and said 'you're going to be challenged' and he just went. If he'd done what Helen did and [said] 'bring it on I think he would have had the votes, but I don't think he ever had the appetite for it."