Labour's Judith Tizard and National's Nikki Kaye share an electoral tightrope. Whoever wins the seat of Auckland Central will breathe easy on election night. Lose and it could be a nail-biting evening.
That is because neither candidate is assured of a seat on her party list.
Tizard, who has held Auckland Central since 1996, is one of several low-ranked electorate MPs who have been given a message that they may be on the way out. She has a list ranking of 38, well down on her 18th spot in 2005.
And Kaye is 57 on National's list with 19 list-only candidates above her. Any slippage in National's high poll ratings will not favour the 28-year-old, one of several young candidates the party wants to get over the line.
Kaye joins a list of National hopefuls who have wooed the socially liberal voters who live in the expensive inner-city suburbs of Herne Bay, Ponsonby and Grey Lynn and shop for organic vegetables. In 2005, Pansy Wong fell 3884 votes short of Tizard.
Auckland Central has the highest 20-to-29-year-old population in the country and a growing population of central city apartment dwellers, which has jumped from 17,135 in 2005 to more than 21,500 this year.
Reaching this group is difficult on foot or by expensive letter drops when candidates have a campaign spending limit of $20,000.
It will take a 14.1 per cent swing for Kaye to win the Labour stronghold, but, more likely, the seat will be determined by the Green vote.
At the last two elections, the Greens' Nandor Tanczos won more than 5000 electorate votes to go with a very strong party vote.
Tanczos is not standing this year and in his place is Denise Roche, a Waiheke Island resident and Auckland City councillor. She is relatively unknown on the mainland and is focusing on the party vote.
According to an unnamed centre-right commentator, the arithmetic is simple. National needs to eat into the Green vote. It cannot win with just its own vote. If Green voters switch electorate votes to Labour, Tizard is safe.
That is not troubling the motivated Kaye, who is running a vigorous and old-fashioned door-knocking campaign. National Party sources say that although raised in conservative Epsom and Kohimarama, she is more socially liberal and environmentally active than most in the party.
On the other hand, Tizard has more than 40 years of family political history and nous to draw on. Name recognition, strong links with the gay and other communities and being a junior minister in transport and the arts help. Then again, she has received criticism for her now-defunct role of Minister for Auckland Issues.
Next door in affluent Epsom, a tactical game is going on between Act and National.
In 2005, Act leader Rodney Hide ran a "desperate and furious" campaign to unseat National's two-term MP, Richard Worth, by 3102 votes and give the right-wing party a parliamentary lifeline.
Worth, who became a list MP, is standing again, but says he is firmly concentrating on increasing National's party vote of 58.5 per cent in 2005 to 70 per cent.
"How people decide to cast their constituency vote is an issue for them."
With Act polling well below the 5 per cent threshold to gain list seats in Parliament, National needs Hide to win Epsom and hopefully provide two or more Act MPs for a National-led coalition.
Still on the Auckland isthmus, the Labour-held seat of Maungakiekie is considered an outside chance by National. Labour MP Mark Gosche is retiring after three terms and the loss of Otahuhu from boundary changes reduces Labour's majority of 6450 in 2005 to about 4000 on paper.
Labour is replacing one unionist (Mr Gosche is a former national secretary of the Service and Food Workers Union) with another, Carol Beaumont, secretary of the Council of Trade Unions.
Mr Gosche's parliamentary career has been hit by two family tragedies - his wife had a cerebral haemorrhage three years ago and a son died last December.
Samoan-born Peseta Sam Lotu-Iiga is the National candidate. Not only is he among a new bunch of young, highly educated 28-to-45-year-olds offering new blood and values for National, but he is also part of an attempt to boost the party's ethnic diversity.
National's Belinda Vernon won the seat in 1996 and the party's fortunes are strong across the city.
Mr Lotu-Iiga, who got a taste for politics last year when he won a seat on the Auckland City Council, believes the race is competitive, but says it is more important to win the party vote.
The politically hardened Beaumont says Labour's support is pretty solid, but she is taking nothing for granted.
The electorate is a collection of different communities, such as Onehunga, Panmure and Ellerslie, and ethnically diverse. Asians account for 22 per cent and Pacific Islanders 18 per cent.
Sitting MP: Judith Tizard (Labour).
Background: Former restaurant owner with politics in her blood. Member of Auckland Electric Power Board and Auckland Regional Council before becoming MP for Panmure (1990-1996). MP for Auckland Central since 1999. Junior Government minister since 1999.
Main challenger: Nikki Kaye (National).
Background: Lawyer, businesswoman and entrant in Coast to Coast marathon.
Frontrunner: Carol Beaumont (Labour), selected to replace retiring MP Mark Gosche.
Background: Secretary of the Council of Trade Unions since 2003. Member of Gosche's team for nine years.
Main contender: Peseta SamLotu-Iiga.
Background: Cambridge University MBA graduate. Former lawyer and financial analyst. Current Auckland City councillor.
Sitting MP: Rodney Hide (Act).
Background: Founding president of Act (1994), leader from 2004 and Epsom MP since 2005. Former economics lecturer.
Main challenger: Richard Worth (National list MP).
Background: Lawyer who replaced Christine Fletcher in Epsom in 1999. Lost seat to Rodney Hide in 2005.