Safe seats left empty after controversies and one of Parliament's longest-serving MPs facing a tough fight to hold his electorate - here's what to look for in the South Island.
Banks Peninsula
The contest in Banks Peninsula is set to be closer than in past elections and will result ina new face in Parliament - an identical twin and city councillor, or a union organiser with a PhD in psychology.
The incumbent, Labour veteran Ruth Dyson, is retiring and boundary changes have added National-leaning neighbourhoods.
The seat covers much of the Lyttelton Peninsula, and is a new electorate - containing most of the old Port Hills electorate and Banks Peninsula, more rural and formerly part of the National stronghold of Selwyn.
Last election Dyson won Port Hills by nearly 8000 votes, but more people voted for National (40.7 per cent, compared to Labour's 39.4 per cent and the Greens' 10.29 per cent).
Dyson's retirement and the boundary changes could make the contest more marginal.
Labour has selected Tracey McLellan, the party's senior vice-president and organiser with the NZ Nurses Organisation. McLellan holds a PhD in psychology and worked for some time in clinical research into dementia and childhood brain injury.
National's candidate is Catherine Chu, an identical twin who started university at 15 and began her career in private banking at 18.
Now in her 20s, Chu is an elected Canterbury DHB member and became a Christchurch City councillor last year, representing Riccarton, where she was raised by her parents, who moved to Christchurch from South Korea. She sits on the council with McLellan's son, Jake, who represents the central ward.
Other candidates include Green Party MP and Conservation and Land Information Minister Eugenie Sage, who got nearly 7.5 per cent of the vote last election, and whose work in the last term included launching an agreement towards a pest-free Banks Peninsula.
Southland
An electorate that has always been held by the National Party has proven something of a curse for the previous couple.
Hamish Walker was MP for Clutha-Southland for just one term before resigning after leaking the details of Covid-19 patients to the media.
Walker had taken over from Todd Barclay, who stood down at the last election after a scandal involving secret recordings of staff members.
The electorate - previously held from 1996 to 2014 and with less controversy by former Prime Minister Bill English - has been renamed Southland after 2020 boundary changes in which it gained the part of Central Otago around Alexandra and Roxburgh from Waitaki, and lost areas around Balclutha to the new Taieri electorate, and around Tuatapere to Invercargill.
National has selected 41-year-old Queenstown lawyer Joseph Mooney to replace Walker, and he's all but assured victory.
However, opponents will seek to chip away Walker's 14,354 majority and help grow their party's vote.
Labour has selected Jon Mitchell, who has worked in tourism and emergency management, and David Kennedy has been selected by the Greens.
Southland is one of the largest in the country in terms of land mass - covering Queenstown, Arrowtown, Clyde, Gore, Mataura, Winton, Lumsden, Te Anau, the Catlins and most of Fiordland National Park.
In 2018, Southland ranked first among general electorates for people aged over 15 who were in full-time employment, but has been hit hard by Covid-19, given the region's strong tourism sector (more than one in 10 people working were employed in accommodation and food services).
Nelson
Labour will fancy its chances of upsetting long-serving National and Nelson MP Nick Smith after the left vote was split last election.
In 2017, Labour did better in the party vote than National for the first time since 2005, and Smith's personal vote majority was slashed to 4283 after a strong run by Labour's Rachel Boyack, who works as a health and safety co-ordinator for the Anglican Diocese of Nelson.
Boyack is running again, and if she wins would be Nelson's first female representative.
Smith has held the seat since 1996, winning eight elections.
The Greens had targeted Nelson for the electorate vote but Labour refused to give them a clean run, and the standoff may have ruined Labour's chance to take the seat. This year the Green candidate and political newcomer, geologist Dr Aaron Stallard, says his emphasis is the party vote.
Lawyer Sue Grey is running for the NZ Outdoors Party and teacher and businessman Chris Baillie will stand for Act.
Nelson is the only electorate to have existed continuously since the first Parliament in 1853. Boundary changes in 2020 shifted Brightwater into the West Coast-Tasman electorate.
Taieri
Boundary changes mean the Labour stronghold of Dunedin South takes in new territory to the south, and has been renamed Taieri.
The old Dunedin South was easily held by Labour MP Clare Curran, but the boundary changes will make Taieri more rural and a happier hunting ground for National, which has talked up its chances of an upset.
Curran is retiring from politics, and Labour has chosen her replacement in former lawyer, TV3 journalist and director of the British Council NZ, Ingrid Leary, who moved to Dunedin late last year from Waiheke.
National's candidate is Liam Kernaghan, who previously worked in Wellington as a political adviser to Amy Adams and Simon Bridges. Also featuring is NZ First MP and farmer Mark Patterson.
The electorate is 90 per cent NZ European and one of the oldest - more than one in four of the population are aged over 60.
Invercargill
The looming closure of the Tiwai Point aluminium smelter will be a feature of the race for the Invercargill seat, which is open after the retirement of incumbent and National MP Sarah Dowie.
Penny Simmonds has been selected by the National Party and has taken campaigning leave from her position as chief executive of the Southern Institute of Technology.
Her opposition is Labour list MP Liz Craig, who before entering Parliament in 2017 was a public health doctor. Craig lost to Dowie in 2017 by 5579 votes.
National has held the seat since 2005, taking it off four-term Labour MP Mark Peck. The electorate has shifted between National and Labour since 1935.
Aeronautics engineer Joshua Gunn is running for NZ First and barrister Rochelle Francis for the Green Party.
Invercargill takes in the communities of its namesake, Bluff, Stewart Island, Riverton, and Wallacetown; its western boundary extends into the Fiordland National Park.