An astonishing dead heat in the Christchurch Central electorate has left the National and Labour candidates sweating on the result of special votes, with both saying they might end up seeking a recount.
The Labour incumbent Brendon Burns and National's Nicky Wagner are tied with 10,493 votes each after the initial count, after a substantial swing to the right across earthquake-ravaged Christchurch that ate into Mr Burns' 2008 majority of 935 votes.
Mrs Wagner said the tied vote left her with a feeling of "absolute euphoria" because the electorate had never been held by National, and had traditionally been viewed as Labour's "jewel in the crown".
"I have gradually chipped away at [the Labour majority], and now it's the most marginal seat in the country."
Mr Burns, a former journalist, said he "just liked to ensure the journos get a good story", but no one could have anticipated a tie in their wildest dreams.
"Obviously I knew it was fairly tight, but I thought we were going to be a bit ahead."
The available records leave it unclear whether there has been a dead heat in a New Zealand electorate before, but political scientist and historian Alan McRobie said he could find no record of such a result since 1969.
The next closest result he could find was in 1987 when Labour's Reg Borman was declared the winner in the Wairarapa seat by one vote. A court later ordered Mr Borman to forfeit the seat to National's Wyatt Creech after it was found he had overspent on the election.
Both candidates have been left to ponder what if they had managed to win over that one extra voter. "Of course we could have done more if we had known, but where would you put [the effort]?" Mrs Wagner said.
Mr Burns said: "You do go through that. But I went to bed on Friday night quite late... thinking I couldn't have worked any harder."
Mrs Wagner rated her chances of winning the special vote count within the next two weeks as very good.
"With the swing to National, and the fact that we've been working very hard with our special votes, I think we will win them."
But Mr Burns was equally confident. "Traditionally, incumbents tend to be favourites for specials. I think it's a bit like the France-All Blacks game. I'll be very happy if it's a close result, but clearly it would be nice to have a bit of a margin."
If it's still tight after the special votes are counted, there is the prospect of both candidates seeking a recount.
"With thousands of votes pouring through booths, there's always the potential for slip-ups to happen," Mr Burns said. "So we're watching things very closely, we're assembling a team to do that."
Mr Burns, who is due to fly out next weekend to South Africa for a climate change conference, will take advice from Labour's hierarchy on whether he should still go.
Although Labour has held most of its traditionally safe Christchurch electorate seats, the election saw its party vote slump against National.
Earthquake Recovery Minister Gerry Brownlee, who was re-elected in Christchurch's Ilam electorate, said that it was inevitable the earthquakes would play some part in voters' thinking.
"I think people can't do anything other than ask themselves 'how has the Government handled this?' I think from that perspective, quite clearly people have given the Government a bit of a tick on that."
Otago University political scientist Bryce Edwards said the Government's handling of the quakes played an important role in the increase in support from Christchurch.
"There's just so many factors in there it's hard to separate them out, but certainly the earthquake is the big issue, and the fact the Government has been very visible in Christchurch.
"It's almost been like an election advertisement for the incumbent Government, not the actual MPs there who are mostly Labour."