The National Party says it is not tenable that senior Labour MP Michael Wood stays on as a minister of anything, after this week's airport shares debacle.
A Parliamentary inquiry has been launched and Wood has temporarily lost his transport portfolio, after he failed to disclose and sell his shares in Auckland Airport.
It has been revealed he appeared to have misled reporters and former prime minister Jacinda Ardern over his shareholding.
Wood told the Cabinet Office numerous times he would dispose of the shares, but had failed to do so, Prime Minister Chris Hipkins said during a post-Cabinet stand-up this week.
"Having indicated back in 2020 that he was intending to dispose of them, he should have done that," Hipkins said.
National's deputy leader Nicola Willis told Morning Report it was not the mistake that mattered, it was the putting right.
"I think in this instance, we would all have sympathy for Michael Wood if he made an original error and then he corrected it, but this went on for two-and-a-half years," she said.
"He had multiple people involved, telling him to sort it out, and I still haven't heard an adequate explanation as to why he was unable to do that."
She noted he had managed to sell the shares very quickly this week.
Wood was given multiple "real warnings" about the shareholding issue, Willis said.
"The Cabinet Office being in touch to say 'you have to deal with this conflict of interest, what are you doing about it?' that's a pretty serious communication to be engaged in.
"Having the prime minister asking you what you've done about it - that's pretty serious."
Willis said Wood's actions raised questions about whether he took the rules seriously.
"Did he think that in some way he was above them or they didn't matter, or they didn't apply in his case?"
Asked whether she believed Wood should be sacked over the issue, Willis said: "Yes, because it's not just one offence, this is a saga that went on for two-and-a-half years."
She admitted she had recently made an error in a declaration of her own pecuniary interests, but said she had moved quickly to correct the record.
"This year in my pecuniary interest, the minute it came out I saw that it didn't include the mortgage on my family home. I wrote to the register, I said 'this is an error, the error is mine, please can it be corrected'," she said.
"Obviously I regret that, but the point here is when errors are made, it is the putting right that counts."