NZ election 2020: The biggest winners and losers from Judith Collins' National caucus reshuffle

Two former leaders are joining Judith Collins in her shadow Cabinet, and potential dissenters are being kept busy with big new portfolios.

A reshuffle can swiftly turn smiles upside down. First thing's first, shutting down her competition Mark Mitchell, the only other contender for the leadership job.

Mitchell loses his justice portfolio to Bridges and drops six rankings, punished for his two attempts at leadership - although that's not how he sees it.

"Some people might interpret it like that - I don't," he said. "She's the incoming leader and she has the right to pick the team she wants."

Mitchell pledged his loyalty to Collins on Thursday, like he has all his leaders - "whether it's John Key, Bill English, Simon Bridges, Todd Muller or Judith Collins".

Collins also rewarded former leaders and their faithful, with Todd Muller coup conspirators Nicola Willis and Chris Bishop promoted up the ranks.

National's last reshuffle didn't go so well - there were no Māori MPs on the front bench. There are now two Māori MPs up there - Simon Bridges and Dr Shane Reti.

There are only two women in the top 12 - Willis and Collins herself - but National's new leader says diversity is about "diversity of thought - and that is what I've put together".

Collins has kept some loyalists close too.

David Bennett, a close friend to Collins, once brazenly told a constituent he was working on rolling Bridges. He's in the top 12 and takes up the agriculture portfolio.

Collins' deputy remains campaign chair and looks after our spy agencies - and although Brownlee once offered his resignation after charging through airport security, he's now in charge of National's COVID-19 border response.

The Government's sitting back and watching the reshuffling and exodus with glee.

Though they wouldn't say so publicly - Prime Minister Jacinda Ardern says she doesn't engage in opposition politics - while having a massive dig at the Opposition's politics.

"Some of the issues the Opposition are facing - their inner turmoil - it's a matter for them," Ardern said.

Collins is wasting no time. On day one she brought down the axe on former health spokesperson Michael Woodhouse and on day two announced a major reshuffle.

On Friday, day three, she's making the infrastructure announcement predecessor Muller was supposed to on Tuesday. National's hailing it as the biggest infrastructure package ever.