And Chris Finlayson has doubts the coalition, made up of National, NZ First and ACT, will make it to the election campaign intact.
Tensions between NZ First and National have risen this week, after NZ First leader Winston Peters' office released internal emails regarding New Zealand's stance on the US strikes against Iran. They showed Prime Minister Christopher Luxon's preference was to support the US action. New Zealand ultimately did not express support, after Peters intervened.
Peters on Thursday said it was a mistake to release the emails without first speaking to Luxon's office. National accused Peters of putting "ahead of the national interest", and National deputy leader Nicola Willis called Peters "very, very confused".
Former National Cabinet minister and Attorney-General Chris Finlayson said while he had no reason to doubt Peters that it was a "mistake", it was a "peculiar set of events".
"These are the sorts of exchanges that you would not expect to be released under the OIA because there's a carve-out for this kind of sensitive material.
"And also as to the process, well, it was appalling where you've got multiple ministers involved in the creation of emails and documents, you would expect their officers to be consulted. So he says it's a mistake. And there we have it."
He said he had "no time" for NZ First, calling the party "an excrescence".
"Every time any political party, any major political party deals with them, you get that sort of nonsense."
He said he agreed with former Labour Party Prime Minister Helen Clark that National and NZ First were "eating one another for votes".
"I have long maintained that when you're dealing with New Zealand First, things can go sour very quickly. They are, I think sometimes you refer to people as frenemies, but I wouldn't even go that far. I think they're the enemy. And I think the best thing the National Party can do is try and extricate themselves from this grisly coalition and declare war on New Zealand First…
"I wonder whether this thing will go full term. It just seems to me every time New Zealand First is in government, you get these kinds of sideshows. Are they acting in the public good, in the national interest? Well, I don't think they ever have.
"I think that people are sick of it... Are people interested in this sort of low-level stupidity? They're more interested in the cost of living, in airfares and questions like that."
Finlayson declined to comment on what the pros and cons a snap election would hold for National.
"Well, you see, I'm what you call a FIP, a formerly important person, totally washed up on those sorts of major strategic questions, you need really to talk to those who are actively involved in the arena at the present time."
