Former Waitakere Mayor Sir Bob Harvey says National MP Hamish Walker leaking the details of New Zealand's COVID-19 patients has "guaranteed a Labour victory" come September's election.
Ex-National Party President Michelle Boag admitted on Tuesday to passing on the patient information to Walker, who subsequently sent it to three media outlets.
Walker also outed himself on Tuesday and has been told by National leader Todd Muller to fully cooperate with an inquiry into the breach. Muller stripped him of his portfolios and on Wednesday said he's lost trust in the Clutha-Southland MP.
Speaking on Tuesday evening, Sir Bob said the saga had set Labour "on their way to the tape".
"It's guaranteed a Labour victory - believe me," Sir Bob told Magic Talk's Ryan Bridge.
Boag said the patient information became available to her in her role as acting chief executive of the Auckland Rescue Helicopter Trust and has since resigned. Sir Bob said he couldn't believe what had unfolded.
"She's [Boag] been around in politics 40 years - did she not know this is traceable? It leads right to her."
But Former National and ACT leader Don Brash, appearing on Magic Talk with Sir Bob, questioned how Boag came to get the information.
Brash said New Zealand's COVID-19 patients were in isolation and have "nothing to do" with the Auckland Rescue Helicopter Trust.
"How did this stuff leak? It's embarrassing, I think, for the Government and The National Party.
"It's disgraceful that this information got out. I blame the Government administration at least as much as I blame Michelle [Boag] and Hamish Walker.
"This leak out of a Government department should never have come out of a Government department - it's ridiculous that it came at all."
Health Minister Chris Hipkins said on Tuesday the leak had a "ring of dirty politics to it".
In a statement, Walker said 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". As well as resigning from the Auckland Rescue Helicopter Trust, she's since stood down from Auckland Central MP Nikki Kaye's campaign committee.
"I very much regret my actions and did not anticipate that Hamish would choose to send it on to some media outlets," Boag said on Tuesday.