Simon Bridges says moves in the Labour Party to make it easier to replace their leader shows Jacinda Ardern is "around for a good time, not necessarily a really long time".
Labour members this weekend will vote on simplifying the party's leadership process. The current system, introduced in 2012, uses a kind of electoral college - caucus getting 40 percent of the vote, members another 40 percent and affiliated unions 20 percent. The only exception - as happened in 2017 - is when a leadership vote takes place within three months of a general election.
When Andrew Little stepped aside, Ardern was nominated and elected unopposed by the party's MPs, without a lengthy election process involving members and unions. The two previous elections saw David Cunliffe (2013) and Little (2014) emerge victors despite neither being caucus' preferred pick - both times, the party's MPs overwhelmingly preferred Robertson. Cunliffe was popular with the party's membership, while Little was backed strongly by the unions.
Labour this weekend will meet virtually to discuss an alternative - allowing caucus to choose a new leader without input from the membership or unions if two-thirds of them agree. Other options on the table include making the threshold 75 percent, or making the simplified leadership process only applicable while the party is Government.
Party president Claire Szabo told the NZ Herald a wider leadership battle made sense in Opposition to get media coverage and showcase candidates, but not when in Government.
Robertson will be backing the proposal, Bridges told The AM Show on Friday.
"He's had a go two or three times I think before, and he'll have a sense that you know, he is the power behind the throne, behind Ardern, and he'll be wanting his turn…. I do think the fact that they are changing the rules, they're not doing that for no reason. You can bet your bottom dollar Grant Robertson wants those rules changed."
The latest Newshub-Reid Research poll, released in August, had Labour on 43 percent, 14 points clear of National, and Ardern on 45.5 percent as preferred Prime Minister, 37 ahead of National's Judith Collins. Ardern's polling was down 2.6 percent on July - inside the margin of error.
"I think it's very interesting that they are doing this," said Bridges. "It does say to you and me and I think probably New Zealanders quite clearly that Jacinda Ardern is around for a good time, not necessarily a really long time."
Ardern, who unexpectedly became Prime Minister with the help of the Greens and New Zealand First in 2017, has had an eventful Prime Ministership to date. In just four years she's had to deal with the world's biggest pandemic in a century, New Zealand's deadliest volcanic eruption since Mt Tarawera in 1886 and the country's worst-ever terrorist attack. She also became a first-time mother in 2018.
Labour's David Parker, appearing on The AM Show with Bridges, said there was "no conspiracy".
"The reason the rules are being changed is we changed it the other way a few years ago and it hasn't worked very well... I'm very, very confident the Prime Minister will still be standing at the next election and she'll win."
Parker himself went for the leadership in 2014, but was the second candidate of four eliminated after Nanaia Mahuta. Both now have senior roles in the Ardern administration. He said he won't be trying again.
"Never say never, David," said Bridges, who's been the subject of constant leadership spill rumours since being rolled in 2020, considering the party's downward polling trajectory ever since.
Bridges again ruled it out, saying he might have a "credibility issue" since no one believes him.