Stuart Nash Photo: RNZ / Dom Thomas
Former Cabinet minister Stuart Nash's communications with donors will be reviewed to see if there have been any more breaches of the rules.
Prime Minister Chris Hipkins says his office was aware of an email the now-sacked minister sent, which breached Cabinet confidentiality.
But National Party leader Christopher Luxon says it is a cover-up.
Napier MP Nash was stripped of all his ministerial portfolios on Tuesday after it emerged he sent an email to senior business figures in 2020 which contained Cabinet discussions related to a commercial relief package being negotiated. Nash was small business minister at the time.
Speaking to media on Wednesday afternoon, Hipkins revealed the Prime Minister's Office was made aware of the email in 2021, when it was included "in consultation around an Official Information Act request".
"It was deemed to be outside the scope of the Official Information Act request in question," so was not made public, Hipkins said.
He said neither then-Prime Minister Jacinda Ardern, nor her chief of staff, were alerted to the email's existence.
"I have made it very clear to my office that I expect to be alerted about any such matters should they arise, and should my office become aware of them."
He said he did not believe it was deliberately covered up.
"I can't speak to the consideration of it at the time - I was not the prime minister at the time ... I was not involved in that."
Nash was already on a "final warning" after a number of errors, including asking the police commissioner to appeal a sentence, calling for a man yet to face trial to be imprisoned for "many years", and asking an official at the Ministry of Business, Innovation and Employment to look at immigration case he wanted sorted out, bypassing standard procedures.
The review, to take place over the next two months, aims to find out whether Nash has breached Cabinet collective responsibility or confidentiality on other occasions, or if there have been perceived or actual conflicts of interest.
"The scope of this review will be limited to emails, texts and other messages between Stuart Nash and any declared donor to his campaign," Prime Minister Chris Hipkins confirmed on Wednesday.
"Stuart Nash has assured me he will fully cooperate and I expect to have an outcome in the coming months, prior to the general election."
Hipkins said Nash had assured him, prior to the 2020 email being made public on Tuesday, that there were not any other instances or allegations of misconduct.
"I expect a high level of conduct from ministers and MPs and his actions raise perceptions of influence which cannot stand and therefore need to be checked."
He said he was yet to speak to Nash about this new revelation.
Luxon said it was a two-year cover-up, and raised questions about the culture in the prime minister's office.
"It's a cover-up because you've actually got an email exchange between the Prime Minister's Office and Stuart Nash's office, an official information act request for information that was declined ... and it sat there for the last two years.
"Then you've got an admission from the prime minister saying neither he nor the previous prime minister apparently - or their respective chiefs of staff - were aware of the issue, but clearly people inside the prime minister's office were aware of the issue.
"What kind of culture is it if you don't actually flag those issues higher up the chain?"
He said the review should be looking at all correspondence from Nash since 2017 in all his portfolio-related interactions, "whether they be donors or whether they be others he may have traded Cabinet information - sensitive, confidential Cabinet information - with as well".
"You want to be sure there isn't a pattern of behaviour here that goes on and on."
Luxon said Nash should no longer be an MP, and a by-election should be held.
"I think Stuart Nash needs to leave this place - last night, today - because essentially he's actually breached trust on a serious issue."
Hipkins said a wider review looking at all of Nash's ministerial communications would be "a very, very large undertaking, and I've not seen any suggestion that is required here".
"We'll await the outcome of this review before deciding if anything further is required."
Nash was yet to reveal if he planned to stand in Napier again. Hipkins said he had a "fair idea" of Nash's plans, but would not be drawn on what they were, saying it was "Stuart's announcement to make".
Nash has now apologised after being sacked.