This week marks the 25^th anniversary of the New Zealand’s first MMP election. Over the last quarter century, the MMP electoral system has led to our Parliament becoming more socially and ethnically diverse, more gender balanced, and to a wider spread of political opinion gaining representation. Or, as one of my former colleagues observed somewhat ruefully at the time, Parliament starting to look a little more like the rest of New Zealand. 

As we celebrate that milestone, it is worth noting that – contrary to the dire predictions of some of MMP’s original opponents – the arrival of multi-party governments has maintained political stability and broad policy continuity. The various political parties in government over that time have quickly developed the modus operandi to make that work, and while there have been differences within governments, there has rarely been the instance of the small party tail wagging the large party dog the way some feared would be the case. 

But rather than strengthen the positive features the MMP system has brought to our system of government, the current government is currently considering a measure that will limit the ability of smaller parties to gain and retain representation in the future. It has established an independent electoral review to look at, amongst other measures, changing the threshold for representation in a way that could have a detrimental impact on small parties, Te Pati Māori, in particular. 

The 1986 Royal Commission that proposed our MMP system originally recommended that the party vote threshold (the minimum vote required to gain party list seats) be set at 4%, or, if a party won an electorate seat, for all its party votes to count, regardless of whether they reached the 4% threshold. In effect, that meant a party winning one seat needed about 1.2% of the party vote to win its first list seat. 

At the time, Parliament’s then two-party Labour-National club decided that the Royal Commission’s recommendations were too generous and might lead to an unacceptable proliferation of new and small parties in Parliament which could be destabilising for democracy (in other words, a threat to their monopoly). So, together, they increased the Royal Commission’s recommended threshold to 5%, but left the one-seat rule untouched because both thought it unlikely many, if any, parties would gain representation this way. 

By and large, they have been right. Outside the Māori seats, where special dynamics have applied, since the advent of MMP only 5 general seats have elected Members from outside either Labour or National. In the current Parliament only one general seat and one Māori seat have non-Labour or National Members. Moreover, on only three occasions (the Progressive Party in 2002, UnitedFuture in 2005 and Te Pati Māori in 2014) have parties with Members elected via the one-seat threshold been part of governing arrangements, and even then the total number of Members elected this way over those three instances was just 4. On three other occasions (New Zealand First in 1999, ACT in 2005 and Te Pati Māori in 2020) a total of 5 Members have been elected via the one-seat rule, but they were not part of governing arrangements at the time. 

Whichever way one looks at it, the impact of the one-seat threshold has been limited. In the three instances where it played a role in government formation, the lead party of government (Labour in 2002 and 2005 and National in 2014) would likely have remained in office, regardless of the application of that threshold. That says the pejorative argument that parties, large and small, have been using the one-seat rule to manipulate government formation has little real weight. 

At the same time, what is clear, though, is that the one-seat rule has helped small parties get representation, but without significant distortion to the overall make-up of Parliament. (The biggest number of Members at any one time elected via the one-seat rule was 3 New Zealand First MPs in 1999.) 

If the independent review upholds the government’s previously stated policy intent to abolish the one-seat rule from 2026 it will also need to recommend a substantial reduction in the party vote threshold to compensate for the impact on small parties. Current thinking seems to be to revert to the 4% proposal of the Royal Commission, but, effectively, without the one-seat rule, this would still leave the representation barrier higher than the Royal Commission thought desirable. 

If the one-seat rule is abolished, a fairer and more realistic party vote threshold would be in the region of 2% to 3%, but the chances of that happening are remote. For its part, National has already said it will oppose any reduction in the party-vote threshold, but its position on the one-seat rule is more ambiguous. The worst outcome – but the one Labour and National have historically inclined to – would be keeping the party vote threshold at 5% and abolishing the one-seat rule. 

That would suit their common self-interest very well but would be bad for democracy overall. It would further limit the already difficult prospects new and emerging parties face to gain representation and would have a particular impact on Te Pati Māori. Were the one-seat rule to be abolished, as things currently stand, Te Pati Māori would lose its solitary list seat. Moreover, as its power base is concentrated in the Māori seats, its prospects of reaching the 5% of the total vote threshold will always be much more difficult than for other parties. For that reason, there is a case for considering a lower party vote threshold for Māori-based parties, although that would be extremely difficult to institute in practice and would almost certainly be divisive, so is unlikely. 

There is a fundamental principle at stake here which is in danger of being overlooked. The basic role of the electoral system is to provide a fair process for the election of our Parliament. An inherent part of that is ensuring that the system is so designed to enable the widest possible expression of political opinion, which is more than just looking after Labour and National. Provisions that unreasonably restrict or marginalise that opportunity should be rejected. Instead, within the confines of the system, the focus should always be on enhancing and promoting the opportunities for political expression and representation, not limiting them. Were that principle to be applied to the current consideration of electoral law changes, the fixation to do away with one-seat rule would be immediately and solidly rejected.