It is a truism that this has been an extraordinary election campaign. After all the shouting and the tumult of the last three months, there has been very little movement for either of the blocs in that time. Support for the centre-right has barely shifted, while support for the centre-left has moved upwards by less than 1%. After an early surge, support for the newcomer Opportunity Party has slipped back to where it was three months ago, but it could still prove critical in the formation of the next government.

Over recent weeks there has been much talk of the potential impact of the “overhang” – the situation where a party wins more electorate seats than its share of the party vote would normally entitle it to receive. The strategy was initiated by Te Pāti Māori when it announced it would be seeking the electorate vote only in the six electorates it currently holds, and urging its supporters to give their party votes to either Labour or the Greens in the hope of engineering a change of government.

In recent weeks, as National’s support has stalled, some centre-right strategists have been urging a similar approach, calling on centre-right voters to support National candidates with their electorate vote, while giving their party vote to either ACT or New Zealand First to boost the centre-right’s overall chances of re-election. The strategy is based on the likelihood that National will win the largest number of electorate seats, although it has not been endorsed by National. Nor from recent polling is it clear whether it is having any immediate impact on voter behaviour. Nevertheless, the prospect of a National overhang, contrived or otherwise, is very strong.

What is clear though from the historically low polling figures for both National and Labour is that individual electorate contests are likely to have a more significant impact on the election outcome than in previous elections. And that is where the potential for overhangs assumes greater significance.

So, what will it all mean for the overall election results?

An analysis of the 71 electorate seats suggests up to 41 could be held or won by National; 21 by Labour; 4 by the Green Party; 1 or 2 by ACT; 3 by Te Pāti Māori and one by the former Labour, now Independent, candidate in Tamaki Makarau. Labour could add an additional 13 list seats to its total; the
Green Party could gain 14 list MPs, ACT 13, New Zealand First 12 and the Opportunity Party 8. National would receive no list seats.

Based on latest polling figures, such a result could produce a National overhang of 7 seats (its current potential party vote entitlement is 34 seats), and a Te Pāti Māori overhang of 2 seats (its current party vote entitlement is 1 seat). Should the Independent candidate win Tamaki Makarau, she might also be considered as an overhang. However, given that she is on the ballot paper as a Labour candidate, the Electoral Commission is more likely to count her in the Labour column. If she wins, she could reduce Labour’s list seat entitlement by one.

These overhangs would increase the overall size of Parliament from its normal 120 Members to 129 or even 130 Members. Under this scenario the current centre-right coalition would hold 65 seats and the centre-left (including the Opportunity Party) 64 enough for the centre-right to remain in office, but it would hardly be conducive to a stable government. However, if the Opportunity Party were to talk to National – as the largest party – first and reach a deal with them, the centre-right would have a much more comfortable majority.

Of course, all this is speculation, based on current available information. But since elections always have the capacity to produce surprise results, it would be unwise to rule out other possibilities. The one thing all the pollsters and the politicians have agreed on throughout this election season is that it has been an incredibly tight campaign and that every vote – electorate and party – will count towards the outcome, far more than any of the polling data collected over recent months.

As the campaign draws to its end, there is now little more for voters to do other than cast their votes – assuming they are not one of the more than 1.2 million who have done so already – and await the results.  But, whatever happens, many will be left feeling very uneasy that this election will likely be decided less based on policy options put forward by the various parties than on the capacity for overhangs which the MMP system currently allows.