How New Zealand actually works, MMP

MMP, how the voting works

Two votes on one ballot: one for a local MP, one for a party. The party vote is the one that decides who governs.

What it is

Mixed Member Proportional, MMP, has run every New Zealand general election since 1996. You cast two votes:

The next general election is Saturday 7 November 2026, Electoral Commission, key dates.

• The electorate vote picks your local MP, whoever gets the most votes in your electorate wins the seat, no majority needed. The 2023 election had 72 electorates, 65 general (the South Island is guaranteed 16) and 7 Māori; the 2025 boundary review cut the North Island's general seats by one, so 2026 has 71 — Representation Commission, boundaries finalised August 2025.
• The party vote is the one that counts for power. Each party's share of all the party votes cast decides its share of Parliament's roughly 120 seats, allocated by a formula called Sainte-Laguë: every party's vote total is divided by a series of odd numbers (1, 3, 5, 7…) and the 120 largest quotients each win a seat — Electoral Act 1993, s 191.

Each party first keeps the electorate seats it won; the rest of its entitlement is filled from its party list, a ranked slate the party publishes before the election. A candidate can stand in an electorate and on the list at the same time.

The two doors into Parliament

A party's list seats only unlock if it crosses one of two thresholds:

• 5% of the party vote, the main door; or
• at least one electorate seat, the side door. Win one electorate and the party keeps that seat plus the full list entitlement its party vote share earns, even below 5%. This is the "coat-tailing" rule.

The side door is why electorate deals happen. ACT won Epsom at every election from 2005 to 2023 while its party vote sat below 5%, in 2008, 3.65% of the party vote plus Epsom delivered five MPs; in 2014, 0.69% plus Epsom delivered one — official election results, electionresults.govt.nz. The 2011 "cup of tea", a publicly staged meeting between John Key and ACT's Epsom candidate to signal National voters should back him, made the convention explicit and infamous. The official count shows the split plainly: in 2023 National won the Epsom party vote with 51.5% while ACT's David Seymour won the candidate vote — Epsom electorate detail, official count 2023.

A party that wins more electorates than its party vote entitles it to keeps them all, the extras are overhang seats and Parliament grows to fit. In 2023 Te Pāti Māori won six Māori electorates on a 3.08% party vote (an entitlement of about four seats), so Parliament sat at 122 until National's Port Waikato by-election win added a 123rd, the largest Parliament yet — official 2023 results; Port Waikato by-election, November 2023.

How a government forms

Under MMP no single party has ever won a majority on election night, 2020's Labour win (50.0%, 65 seats) is the only majority government MMP has produced — official 2020 results. So parties negotiate:

• Coalition, parties join Cabinet and vote together; or
• Confidence and supply, a smaller party stays outside Cabinet but promises the government its votes on budgets and no-confidence motions.

After the 2023 election National (48 seats), ACT (11) and New Zealand First (8) spent five weeks negotiating, then formed a three-party coalition under two separate coalition agreements, a 67-seat majority, sworn in 27 November 2023 — official 2023 results; Beehive, coalition agreements, 24 November 2023.

How it came to be

New Zealand voted under first-past-the-post until 1993. Two elections where the second-place party won more seats (1978, 1981) and a decade of governments that broke their manifestos produced a Royal Commission (1986) recommending MMP, then two referendums (1992, 1993) where voters chose it over the old system. A third referendum in 2011 kept it — Electoral Commission, the introduction of MMP.

Keeping MMP in 2011 triggered a statutory review, published in 2012. The Electoral Commission recommended: lower the threshold to 4% (reviewed after three elections), abolish the one-electorate-seat side door and the overhang provision with it, and consider fixing the electorate-to-list ratio at 60:40 — Electoral Commission, 2012 MMP review. Parliament never legislated any of it, changing the core rules needs 75% of Parliament or a referendum, and both big parties benefit from the thresholds that keep small parties weak.

Who decides

The Electoral Commission, independent of government, runs the count, allocates the seats, and conducts the reviews. The rules themselves are the Electoral Act 1993; the voting-system sections are "entrenched", needing a 75% supermajority or a referendum to change — Electoral Act 1993, s 268. Electorate boundaries are redrawn after every census by a statutory Representation Commission.

What it costs

The institution the system fills: an MP's base salary is $168,610 a year (ministers and office-holders more), set by the independent Remuneration Authority — Remuneration Authority, parliamentary determination 2024/25. The Electoral Commission is funded out of the Crown purse; its spending for the 2023/24 year, which covered a general election, is published in its annual report — Electoral Commission annual reports.

Where the arguments are

• Lower the threshold? The 2012 review, the Greens and most electoral-law academics say 5% wastes votes and lets in no genuinely new parties; defenders say it blocks fragmentation and unstable governments.
• Keep the side door? Critics call coat-tailing a rort that lets minor parties survive on tactical electorate deals; defenders say an electorate win is itself a democratic mandate.
• List MPs accountable to whom? List MPs answer to party rankings, not voters, an argument for open lists or more electorates that surfaces every review.

Where to read the primary source

• How MMP works: Electoral Commission
• Electoral Act 1993: legislation.govt.nz; ss 191–193 allocate the seats
• 2012 MMP review: the recommendations nobody adopted
• Official results, every election: electionresults.govt.nz
• Key dates for 2026 General Election: Electoral Commission
• 2023 coalition agreements: Beehive, November 2023

Glossary

The Canterbury of it

The electorate-seat side door has a Christchurch address. Jim Anderton's Progressive Coalition never reached two percent of the party vote, yet sat in Parliament for three straight elections because Anderton held Wigram: in 2002 a 1.7% party vote plus Wigram delivered two MPs, and by 2005 the party's entire caucus was the member for Wigram, the coat-tailing rule run from a Hornby electorate office, not an Epsom one — official results, electionresults.govt.nz.

The city's closest finish came in 2011, nine months after the February earthquake: Christchurch Central ended election night in a tie, the official count put National's Nicky Wagner 45 votes ahead of Labour's Brendon Burns, and a judicial recount stretched the margin to 47 — official 2011 count, electorate results.

And the map itself is young. The Port Hills seat was carved from the old Banks Peninsula electorate in 2008; in 2020 the peninsula moved back in from a fast-growing Selwyn and the seat took its old name back. The boundaries ignore the council's, Waimakariri's MP mostly serves the district across the river, and Banks Peninsula runs from Somerfield out toward Prebbleton — Parliament, Banks Peninsula electorate profile.

Last reviewed 2 October 2026, sources: Electoral Commission 2026 election timetable, Electoral Act 1993, official election results, Remuneration Authority. Corrections: /corrections.