You vote for the party. But who really controls your MP?

In brief

• Under MMP, voters decide how many seats parties receive, but party organisations rank the candidates who fill list seats.

• Opportunity's board can veto coalition agreements, while NZ First's internal committee determines candidate rankings.

• MPs who quit or are expelled don't automatically lose their seats, but parties can seek their removal under waka-jumping laws.

• Vacant list seats go to the next eligible candidate on the original party list, without another public vote.

More than 144,000 New Zealanders voted for Opportunity, giving it seven seats on preliminary results. Yet just two members of its seven-person board could block a coalition deal supported by every one of its MPs.

It's a clear example of how political power can rest with party insiders rather than elected representatives.

And it goes well beyond Opportunity. Under MMP, political parties decide who gets on their lists, influence who enters Parliament and, in certain circumstances, can force MPs out.

So who really controls your party vote once it's been cast?

Who picks the MPs?

Who decides which candidates get into Parliament?

In NZ First's case, a List Ranking Committee decides the order of candidates, with the leader and deputy leader automatically taking the top two positions if they stand.

The committee, made up of senior party officials and nine electorate representatives, has complete discretion over the remaining rankings.

Voters can see the final list, but they cannot change it.

What they cannot do is vote for the party while rejecting individual names on its list.

And while the Electoral Act requires parties to involve members or delegates in candidate selection, parties largely decide how that works. Parliament's own guide says the Electoral Commission does not enforce that requirement.

What if an MP refuses to fall into line?

Suppose a list MP falls out with party leadership, resigns or gets expelled. Can the party take back the seat?

Not automatically. Disagreeing with leadership, or even being expelled from the party, does not itself cost an MP their parliamentary seat.

But the waka-jumping law gives parties a way to force an MP out.

The parliamentary leader must reasonably believe the MP's conduct has distorted, and will continue to distort, the proportional representation determined by voters.

There are safeguards. The MP gets 21 working days to respond, at least two-thirds of the party's parliamentary MPs must support removal, and applicable party rules must be followed.

A party board cannot simply sack an MP from Parliament. The formal power rests with the parliamentary leadership and caucus, subject to those legal requirements.

Former Green MP Darleen Tana discovered how that works. After resigning from the Greens in July 2024, Tana refused to surrender her parliamentary seat.

The party pursued the waka-jumping process, including a vote by party delegates.

In October 2024, Tana lost her seat. The Electoral Commission declared Benjamin Doyle elected from the Greens' existing party list.

No public vote was held.

Can party bosses choose the replacement?

Not exactly. When a list seat becomes vacant, the Electoral Commission must approach the next eligible candidate on the party's original election list.

The party cannot simply nominate somebody new.

But that candidate must still belong to the party and agree to serve.

Under section 137 of the Electoral Act, the Commission asks the party secretary to confirm whether the candidate remains a member. If not, it moves to the next eligible person.

That gives party organisations another source of influence. Their membership decisions can affect who qualifies to take a vacant parliamentary seat.

Unlike electorate vacancies, which ordinarily trigger by-elections, list vacancies are filled from the party's existing list.

The public doesn't get another vote.

Who does your MP answer to?

MMP is designed to make Parliament reflect the party preferences of voters. Party discipline helps preserve that representation.

But MPs are also expected to exercise independent judgment, scrutinise government and represent the public.

Those responsibilities can come into conflict when an MP's political survival depends on retaining the confidence of party leadership.

The public can vote a political party out of Parliament. It cannot directly vote out the officials who govern that party.

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