But there’s a catch: the spending limits only apply to the regulated period, the three months before the election.

This means parties with money to spare have an incentive to get it out the door before spending limits kick in.

This election, the regulated period begins on August 7, meaning political parties with a large war chest have a massive incentive to spend up large before the regulated period kicks in.

For this election, candidates can spend up to $36,000 on election advertising during the regulated period.

A registered party can spend $1,503,000 plus $36,000 per electorate it contests – that means a party contesting all 71 electorates can spend up to $4,059,000 during the regulated period.

Spending that counts towards the cap includes both the preparing and composing of the ads – the creation of them, in other words – as well as buying the space to show them.

Election hoardings in 2023. Photo / Alex Burton

Spending limits force interesting choices on political parties and candidates.

Some candidates will easily be able to raise more money than their spending limit, but would be unable to spend it all during the campaign.

One electorate candidate told me that they paid for a prominent billboard for months before the election, only to give it up during the regulated period because the billboard is so expensive it would have chewed through their spending allowance.

Parties rarely, if ever, hit their campaign spending limits.

In fact, no party in the last three elections has hit its cap. Labour got within $200,000 of its limit in the last election – while National’s expenses came $1m under its spending cap.

The regulated period forces parties to be quite strategic about where they spend their money.

It also levels the playing field between parties that receive lots of donations and parties that do not.

So far, we only have data for donations worth over $20,000 (when donated by a single donor over the course of a year), which have to be declared more quickly than other, smaller donations.

Larger donations tend to favour the parties of the right, while Labour makes up some of the difference in small donations.

Act has collected over $1.5m in large donations this year, followed by National which has collected $770,000, and NZ First which has $500,000.

Opportunity has collected $470,000, while Labour has $400,000, and the Greens have received $280,000. Te Pāti Māori has received $40,000.