Parts of ACT's proposed bill could prove contentious, including making the four-year gap between general elections optional after each election - but only for governments that hand control of select committees to the opposition.
Under the coalition agreements, David Seymour's Constitution (Enabling a 4-Year Term) Amendment Bill is set to pass its first reading within the government's first 15 months.
"I think a lot of people agree that having three years is too short," Seymour told RNZ.
"We'd get careful, considered law-making more often if we had a four-year term. It's about 180 countries in the world that have some sort of Parliament, only three of them work on a three-year term.
"From the point of view of people trying to invest, people in business, people trying to plan their futures, change is never a good thing. In fact, sometimes it's better to have bad policy with certainty than good policy that might change tomorrow."
Parties largely back a longer term
The recent independent review of electoral law had a whole chapter on the length of the term, and proposed having another referendum on the matter. The public rejected longer terms in previous referendums in 1967 and 1990, by 68 percent and 69 percent, respectively.
The current three-year limit is entrenched - meaning it can only be overturned through a supermajority in Parliament or a referendum - so Seymour's bill also proposes a referendum.
NZ First did not respond to requests for comment, but their coalition agreement makes clear they also want the matter to go to a referendum - in fact they wanted one to take place last year.
Justice Minister Paul Goldsmith confirmed the government was planning to deal with both coalition promises in the same bill.
Opposition parties also supported taking another look at the length of term.
"Unfortunately for entertainment value, we're probably going to agree that this is an important question that needs to go to the electorate," Labour's Justice spokesperson Duncan Webb told RNZ.
"I see the arguments for it. My own personal view is I tend to think three years isn't enough for any government to kind of thoughtfully implement their policies. At the same time it's not a question for me, it's a question for the people of New Zealand."
In a statement, Green Party co-leader Marama Davidson said they supported a four-year term "as part of delivering effective government for the long-term wellbeing of people and planet".
However, they wanted it considered in a different way.
"We would like to see this progressed through a Tiriti-based citizens assembly that also considers recommendations of the Independent Electoral Commission such as reducing the voting age to 16."
Goldsmith said National had no position on the idea of a four-year term at this stage, "but we may well develop one over the months to come".
The government's approach would be the same as with Seymour's proposed Treaty Principles bill: withholding support from the Second Reading onwards, at least for now.
"Final decisions about what happens with the bill, whether it's passed, whether there is a referendum, are for the government yet to make," Goldsmith said.
That's despite leader Christopher Luxon voicing his support for a four-year term during the first 1News leaders' debate in September, saying: "I personally have a lot of appetite for that".
Goldsmith said there were good arguments on both sides.
"One of the benefits of course is a longer time for the government to implement its policy agenda, and there's huge disruption when there's a change of government, obviously.
"One of the challenges in infrastructure - in many parts of government - is there's a real cost to chopping and changing as governments change.
"And the alternate argument is around the fact that we have relatively few checks and balances in New Zealand - and so that's an argument for more regular elections."
Te Pāti Māori did not respond to requests for comment.
Select committee provisions could prove contentious
Some of the settings in Seymour's bill - aiming to bring more of those checks and balances into the system - could face more opposition.
"Remember we don't have an upper house, we don't have states or provinces, we've just got one House, one government, that's it," Seymour said.
"The idea of saying 'look, the law stays at three years, but the government can choose four years if they give control of the select committees over to the opposition' - that means there's an extra check and balance.
"So you get more time, but you also get more scrutiny."
Seymour said he got the idea from the cross-party Epidemic Response Committee set up in early 2020, which was chaired by then-National leader Simon Bridges.
The way it would work is the makeup of select committees would - as they do now - reflect the proportionality of Parliament as a whole, but this time with the prime minister and ministers excluded from the calculation.
"The first thing [select committees] would do is elect a chair, and that would overwhelmingly be a chair of the select committee from the opposition - at the moment just about all select committee chairs are from the government," Seymour said.
He said this would make the committees much more likely to recommend changes to the law.
"The select committee could really listen to the submitters and be likely to make changes that the government might not agree with."
Labour's Duncan Webb, freshly into opposition, took a dim view of the idea.
"I'm a lot more suspicious of that. All you'll get is select committees obstructing the work of government, rather than - pretty cooperatively, most of the time - progressing the work of government.
"The select committee process is not one which is intended to approve the bill or not, it's intended to go through and say 'given the bill's intention, does it effectively implement the policy that it's setting out'."
He said it would also violate the constitutional convention that while Parliament is created through the law, it manages itself through things like the Standing Orders.
Seymour argued the government and the voting public would still have the final say.
"If opposition MPs use this extra power irresponsibly, the government's going to use its majority to reverse their changes," he said. "Second of all if they're seen to be acting immaturely or irresponsibly the voters are going to start taking notice at some point and they might find that it's not good for their career prospects."
But Webb rejected that, saying it was not how elections typically worked.
"People vote for policy platforms and politicians - and they have no real visibility of what goes on in the Justice Select Committee or the Economic Development Select Committee. It's a bit of a fiction to suggest that's going to affect electoral outcomes."
He was also concerned it would disrupt the process.
"Ultimately if [the changes] are repugnant to the government, there will be a further tracked bill which simply reverses them all. And that would be done in the Committee stage of the House, so that would be quite disruptive."
Seymour was more optimistic.
"Why shouldn't select committees - whose job is to scrutinise the government and its laws - be dominated by the opposition so long as the government that's elected by the people has the ultimate power to have its way in the end?"
