Jacinda Ardern reveals why David Clark is back in Cabinet and Phil Twyford has been demoted

The Prime Minister has revealed the rationale behind the ruthless demotion of Phil Twyford and shock recall of David Clark to her Cabinet.

Jacinda Arden unveiled her new-look Cabinet on Monday afternoon - and there were a few surprises, including Nanaia Mahuta as Foreign Minister, Andrew Little as Health Minister and Ayesha Verrall as Minister for Seniors.

Among the biggest, however, was her decision to dump former Transport Minister Twyford out of Cabinet entirely, with Michael Wood being handed the portfolio and a place among the Government's most senior ministers instead.

Speaking to media about the decision, Ardern said Twyford has always been an "amazing team member" and described his response to news of his demotion as "quite remarkable".

However she admitted he hadn't done enough to warrant keeping his significant portfolios - especially when it came to his handling of KiwiBuild, a project which represents arguably Labour's greatest failure during its first term back in power.

"I would not keep him as a minister unless I believed he has something to offer, and he does," she said.

"[But] both he and I would acknowledge that in some significant areas - particularly housing - he hasn't made the progress we needed to.

"My decision around reallocating Economic Development was primarily that I wanted it to be held by a minister in provincial New Zealand. This is why I'll be using him in other areas, but he does still have something to offer this team."

Despite being ousted from Cabinet, Twyford still holds the potfolios for Disarmament and Arms Control and Trade and Export Growth. He's also Associate Minister for the Environment and Immigration.

Another shock saw Dr Clark return to the fold after he resigned in disgrace in July, following widespread criticism of him blaming Dr Ashley Bloomfield for the Government's quarantine testing botch-up and a trio of incidents in which he broke his own COVID-19 rules.

The backlash lasted many months, and started when Dr Clark breached alert level 4 lockdown protocol by going mountain biking.

He later admitted to driving 20km to the beach for a walk with his family when Kiwis weren't allowed to drive for recreation, and to moving house when the rest of New Zealand was told they couldn't. 

But Ardern has shown huge faith to offer him another opportunity in her Cabinet, as he takes on the portfolios of Commerce and Consumer Affairs, Digital Economy and Communications, State-Owned Enterprises, Statistics, and the Earthquake Commission.

The Prime Minister said while there were issues with Dr Clark's conduct as Health Minister, she couldn't deny that as minister presiding over New Zealand's COVID-19 response, he played a successful role.

"On this occasion, my view is that we've given a better match to his skillset, in areas where he has enormous value to add," Ardern said. "[This is] particularly in the space around growing the digital economy and digitising the public service."

Among other major decisions, Ardern appointed Grant Robertson her Deputy Prime Minister, made Kelvin Davis Minister for Children and gave the COVID-19 Response portfolio to Chris Hipkins.

Read more about Jacinda Ardern's Cabinet decisions here.