National leader Todd Muller says Hamish Walker leaking the details of New Zealand's COVID-19 patients is "completely unacceptable" and admits he's lost confidence in the Clutha-Southland MP.
Walker on Tuesday admitted leaking the information of 18 cases, after it was revealed last week the patients' names, ages, addresses, and other personal details had been sent to three media outlets.
Muller has told Walker to fully cooperate with an inquiry into the breach, after finding out he was involved on Monday.
"I've demoted him, I've stripped him from his portfolios and I wrote last night to the board outlining my concerns, and they're meeting today [Wednesday]," Muller told The AM Show.
He said he's made it clear to The National Party board that Walker's judgement is "not what New Zealanders would expect and certainly not what I expect".
"His approach is completely unacceptable; not reflective of The National Party I want to lead," Muller said.
Asked by host Duncan Garner if he still had confidence in Walker, Muller said, "In terms of judgement, he's left himself seriously wanting and in that context, I don't".
Walker said his intention behind leaking the COVID-19 patient details was to show holes in Government security systems. Muller said he'd raised "serious concerns" about Walker's actions in the letter to The National Party Board on Tuesday night.
He said after finding out Walker's involvement on Monday, he immediately told him to make contact with his chief press secretary and chief of staff.
"Then, of course, we found out the inquiry was happening and it became very clear to me that we needed to inform that inquiry of what we knew," Muller said.
"I then shared that expectation with Hamish and then I received legal representation, which of course put me in a position, bluntly, of having to check my own legal position before I made it very clear that that information needed to become public.
"Bluntly, that took just over 24 hours but it is what it is - that's how it happened but I was never going to move from the course that this needed to be made public and it was."
It was also revealed on Tuesday the personal details were sent to Walker by former National Party President Michelle Boag. She said the information became available to her in her role as acting chief executive of the Auckland Rescue Helicopter Trust and has since resigned.
Muller said Boag's actions were "appalling".
Any decisions about National Party membership would have to be made by its board, Muller said.
"I think that is another question that the board could reflect on," he said.
"She's been involved [with National] for a long, long time - I don't have a huge amount to do with her at all.
"I think matters of trust are affirmed or otherwise by your behaviour and so, from what I've seen in the last few days, she has lost a lot of trust in my mind."
Health Minister Chris Hipkins said on Tuesday the leak had a "ring of dirty politics to it". Asked by Garner if he believed it was dirty politics, Muller reiterated it was "an appalling lack of judgement" by Walker and Boag.
"Whether you want to put labels in it from our opposite political party - I guess they can choose to do that.
"I'm not going to buy into that conversation. I'm just going to say from my perspective, what's happened here is completely unacceptable."
He said New Zealand's COVID-19 patients were "struggling enough" in isolation without having their details leaked.
Walker said in his statement on Tuesday he's received legal advice and had not committed a criminal offence.
"I sincerely apologise for how I have handled this information and to the individuals impacted by this," he said.
Boag, meanwhile, admitted she made a "massive error of judgement".
"I very much regret my actions and did not anticipate that Hamish would choose to send it on to some media outlets."