David Farrar: How unproportional might the next Parliament be?

MMP is meant to deliver a proportional Parliament. That is how it is designed, and how it was sold.

There is one aspect to it though that can make Parliaments unproportional. It is overhang seats – when a party wins more electorates than their share of the party vote would entitle them to.

We have had overhangs to date, but so far they have not change the outcome of an election. The bloc with the most votes has got to form government. But there is a very real chance that next election, you may get a government that had fewer votes cast for it than the opposition.

The history of overhang seats is:

• 2023: TPM had two overhang seats, winning six electorates but only 3.1% party vote

• 2014: United Future had one overhang seat, winning one electorate but only 0.2% party vote

• 2011: Maori Party has one overhang seat, winning three electorates but only 1.4% party vote

• 2008: Maori Party has two overhang seats, winning five electorates but only 2.4% party vote

• 2005: Maori Party has one overhang seats, winning four electorates but only 2.1% party vote

Parliament normally has 120 MPs, so you need 61 to govern. A one seat overhang doesn’t do much as with a 121 seats, 61 is still a majority.

But a two seat overhang means you need 62 seats to govern, so a bloc that won 61 seats on the party vote could find itself unable to govern.

And on a three seat overhang, a party vote result which saw Bloc A win 61 seats and Bloc B 59 seats could see Bloc B go to 62 seats and govern despite winning fewer party votes.

There are two credible ways this could happen in 2026.

1. TPM win all seven Maori seats but less than 3.5% party vote, which gives them a three seat or greater overhang. National, ACT and NZ First may have got 51% of the effective vote and 61 seats but Labour, Greens and TPM on 49% of the vote form Government as overhang takes them from 59 seats to 62.

2. National wins 44 electorates but has a party vote of less than 33% and they get a three seat or greater overhang. In this case Labour, Greens and TPM may have got 51% of the effective vote, but National, ACT and NZF would get to form Government due to the overhang.

I regard both these outcomes as bad. The Government should be made up of parties than won more votes than the opposition. MMP came in to stop what happened in 1978 and 1981.

I suspect the media would regard scenario 1 as perfectly fine and not newsworthy but regard scenario 2 as the end of democracy and a stolen election.

There are two ways to fix the problem of unproportional results due to overhang. They are:

1. A party that wins more electorates than its party vote entitles it to, simply doesn’t keep them. So if National won 43 electorates, but was only entitled to 40 on the party vote, then it would have the three seats where its candidates got the fewest number of votes go to the second place getter.

2. You increase the size of Parliament so the number of MPs is proportional. This would be only a minor increase if say National won 43 electorates on an entitlement of 40. But if TPM won 7 electorate on an entitlement of four, you would have to increase Parliament by around 75%.

My preference is (1).

David Farrar runs Curia Market Research, a specialist opinion polling and research agency, and the popular Kiwiblog where this article was sourced. He previously worked in the Parliament for eight years, serving two National Party Prime Ministers and three Opposition Leaders