How 399,000 votes could cost Christopher Luxon his majority

Analysis - National's Christopher Luxon has called it an "MMP special", but a shambles might be more appropriate.On the preliminary results, New Zealand is looking at a near-farcical 131-seat Parliament, thanks to a record 11-seat overhang.National's party vote entitles it to 35 MPs, but its lead in 42 electorates gives it an extra seven "overhang" MPs.Likewise, Te Pāti Māori has won five electorates, despite a party vote worth only one MP, adding another four seats to Parliament.That overhang has made all the difference - on a strictly proportional basis, Parliament would be deadlocked at 60 seats apiece.Instead, the existing coalition holds 67 of 131, just one more than the 66 needed to govern.Labour, the Greens, Te Pāti Māori and Opportunity have 64 among them.There is a reason, though, that no-one is celebrating just yet, with an estimated 399,000 special votes still to be counted, roughly one vote in seven.Historically, those votes have tended to favour the left and several knife-edge electorate races remain in play, but there's a catch - the final count could also alter the size of Parliament itself.Here are five ways the numbers could shift when the official results are released on 27 November. Any combination of them could happen at once.Scenario one: National loses electorates to LabourTwo National MPs face particularly nervous waits.In Wairarapa, Mike Butterick leads Labour's Kieran McAnulty by just 139 votes.In Hamilton East, Ryan Hamilton is 456 ahead of Labour's Georgie Dansey.Either seat could yet change hands, although the margins alone tell us little about how the remaining voters have cast their ballots.Because National has more electorate MPs than its party vote affords it, every electorate it loses also reduces the size of Parliament, while Labour's count remains unchanged.Labour's Kieran McAnulty trails National's Mike Butterick by just 139 votes in Wairarapa.SAMUEL RILLSTONE / RNZIf National loses Wairarapa alone, the coalition falls to 66 MPs in a 130-seat Parliament, still a majority.If Hamilton East flips too, the coalition drops to 65 in a 129-seat Parliament. Again, just enough.Scenario two: National takes electorates from LabourThe reverse could also happen, strengthening Luxon's hand.Labour's Michael Wood leads National's Carlos Cheung by just 262 votes in Mt Roskill.In Hutt South, Labour's Ginny Andersen is 889 ahead of National's Chris Bishop.If National overturns either result, its overhang grows, pushing up the size of Parliament.Labour would lose an electorate MP, but bring in another from its list, leaving its total unchanged.National's Carlos Cheung.Liu ChenFor National, every additional electorate victory is effectively a bonus seat.Scenario three: Greens win a Māori electorateIn one of the stranger twists, a Green Party victory would actually hurt the left's chances.In Te Tai Tokerau, Te Pāti Māori's Aperahama Edwards leads the Greens' Hūhana Lyndon by 436 votes.If Lyndon wins, she'll take a seat already included in the Greens' proportional allocation, but Te Pāti Māori would lose one of its four overhang seats, shrinking Parliament to 130.All else unchanged, the coalition would keep its 67 seats, while the other parties would fall to 63.In other words, a victory for the Greens would make Luxon's majority safer.Greens' Hūhana LyndonRNZ / Peter de GraafScenario four: Some of National's party vote shifts to the leftHere's another peculiarity - National could lose party-vote support without losing a single MP.If its vote share drops enough to entitle it to just 34 MPs, it still keeps all 42 of its electorate MPS and its overhang simply grows from seven to eight.That would free up an extra proportional seat for another party, potentially Labour, the Greens or Opportunity.Parliament would grow to 132 seats, but the coalition would still hold 67, against the opposition's 65.Scenario five: Some of ACT or New Zealand First's party vote shifts to the leftThis is one of most dangerous possibilities for Luxon. Unlike National, neither ACT nor NZ First has an overhang protecting its numbers.If either loses a list MP to Labour, the Greens or Opportunity, the coalition's total falls without Parliament shrinking along with it.One lost seat would leave the coalition on 66 out of 131, just enough, but two would leave it on 65, with the other four parties holding 66 between them.In one scenario Opportunity would be kingmaker, in a position to deliver a majority to either side.RNZOpportunity would be kingmaker, in a position to deliver a majority to either side.Of course, any gains for the Greens or Opportunity could come at Labour's expense instead, leaving the overall balance unchanged.The 27 November tangleRemember, any combination of these scenarios could happen at once.Imagine National loses Wairarapa, while NZ First loses a list seat to the Greens.That would leave National with 41 MPs, Labour 36, the Greens 17, ACT 13, New Zealand First 11, Opportunity seven and Te Pāti Māori five.The coalition would hold 65 seats in a 130-seat Parliament. One short of a majority.Now imagine National's party vote also falls enough to increase its overhang, with Opportunity picking up an extra list MP.All of a sudden, we're back to a 131-seat Parliament - but Luxon's side would have only 65 MPs.Labour, the Greens, Te Pāti Māori and Opportunity would have 66 between them.That is just one hypothetical outcome, not a prediction, but it shows how easily a handful of close electorate races and small shifts in the party vote could overturn the election-night result.