Labour's party vote sunk to 27.48% in this election, which is well down on last year's 33.99%. The reason's for their demise can be summed up under the headings of leadership, negative campaigning, the party list, and de-branding.
Phil Goff's leadership leading into and throughout the campaign was poor. His memory and his honesty were constantly called into question and he attacked his opponents in areas which left him open for accusations of hypocrisy.
Instead of concentrating on selling their own campaign, Labour spent the bulk of their time, and advertising money, negatively campaigning on National's policy. There's no doubt that Labour's 'No Asset Sales' campaign stirred up some support, but as often happens with negative campaigning, that support didn't go to the party which was negatively campaigning; instead it went to the Greens and NZ First.
Labour's party list was contentious, even within the ranks of Labour itself. The list presented a party that had not learned from their prior election loss. As a result it saw some sitting MP's who could see their only chance of getting back in via their electoral seat, drop campaigning for the party vote altogether.
So let's take a look at Labour's party vote support by electorate. Note that the following analysis is based 2008 data and preliminary results from the 2011 election.
Biggest Party Vote by Electorate
| Rank | Electorate | Candidate | Party (%) | Change |
| 1 | Mangere | SIO, Sua William | 71.21 | n/c |
| 2 | Manukau East | ROBERTSON, Ross | 65.56 | n/c |
| 3 | Manurewa | WALL, Louisa | 55.85 | +2 |
| 4 | Ikaroa-Rawhiti | HOROMIA, Parekura | 49.53 | -1 |
| 5 | Hauraki-Waikato | MAHUTA, Nanaia | 46.49 | -1 |
| 6 | Mt Roskill | GOFF, Phil | 43.16 | +11 |
| 7 | Te Tai Hauauru | PEKE-MASON, Soraya Waiata | 42.36 | -1 |
| 8 | Tamaki Makaurau | JONES, Shane | 41.35 | -1 |
| 9 | Te Tai Tonga | TIRIKATENE, Rino | 38.88 | -1 |
| 10 | Te Atatu | TWYFORD, Phil | 37.98 | +9 |
Sua William Sio had an outstanding result in Mangere, picking up 71.2% of the party vote, up 9.6% from 2008. Although this rise can be ascribed to the demise of Taito Phillip Field and his Pacific Party (which gained 10.7% of the party vote in 2008).
Labour's traditional powerhouse seats in South Auckland and the Maori seats feature in the top ten. Two notable improvers include Labour Party Leader Phil Goff and Te Atatu's Phil Twyford.
Smallest Party Vote by Electorate
| Rank | Electorate | Candidate | Party (%) | Change |
| 61 | Clutha-Southland | LOO, Tat | 16.15 | -3 |
| 62 | Selwyn | McLEAN, Jo | 16.02 | -7 |
| 63 | Waikato | SUTTON, Kate | 16.01 | -3 |
| 64 | Taranaki-King Country | BARKER, Rick | 15.59 | n/c |
| 65 | Hunua | HILLS, Richard | 15.45 | +4 |
| 66 | Epsom | PARKER, David | 15.28 | +2 |
| 67 | Tauranga | MAHUTA-COYLE, Deborah | 14.60 | -8 |
| 68 | Helensville | GREENBROOK-HELD, Piers Jeremy | 13.88 | +2 |
| 69 | Bay of Plenty | DEVOY-HEENA, Carol | 13.34 | -2 |
| 70 | Rodney | ROSE, Christine | 13.23 | -4 |
Labour's bottom ten list, a mix of rural and affable electorates, is where National is traditionally strongest. Rodney was their worst performing electorate, which saw gains for the Greens, NZ First and the newly formed Conservative Party.
Biggest increase in Party Vote by Electorate
| Rank | Electorate | Candidate | Party (%) | Change |
| 13 | Maungakiekie | BEAUMONT, Carol | 36.78 | +12 |
| 6 | Mt Roskill | GOFF, Phil | 43.16 | +11 |
| 14 | Waitakere | SEPULONI, Carmel | 36.47 | +10 |
| 46 | Botany | WU, Chao-Fu | 23.51 | +10 |
| 10 | Te Atatu | TWYFORD, Phil | 37.98 | +9 |
| 39 | Papakura | MIKA, Jerome | 26.10 | +9 |
| 15 | New Lynn | CUNLIFFE, David | 36.34 | +7 |
| 12 | Mt Albert | SHEARER, David | 37.34 | +6 |
| 41 | Northcote | GILLON, Paula | 24.80 | +6 |
| 55 | Pakuranga | KAUSHAL, Sunny | 18.32 | +6 |
Carol Beaumont did an excellent job in Maungakiekie, picking up 12 spots. As noted above, Phil Goff put in a good showing, along with the two new leadership aspirants Cunliffe and Shearer.
Carmel Sepuloni did an exceptional job in Waitakere, picking up 10 places while managing to pip National's Paula Bennett at the post for the electoral seat.
Biggest decrease in Party Vote by Electorate
| Rank | Electorate | Candidate | Party (%) | Change |
| 21 | Rongotai | KING, Annette | 34.31 | -5 |
| 32 | Nelson | STREET, Maryan | 27.50 | -5 |
| 18 | Waiariki | TE KANI, Louis | 34.80 | -7 |
| 20 | Dunedin North | CLARK, David | 34.49 | -7 |
| 62 | Selwyn | McLEAN, Jo | 16.02 | -7 |
| 17 | Dunedin South | CURRAN, Clare | 35.02 | -8 |
| 45 | Waimakariri | COSGROVE, Clayton | 23.53 | -8 |
| 67 | Tauranga | MAHUTA-COYLE, Deborah | 14.60 | -8 |
| 19 | Te Tai Tokerau | DAVIS, Kelvin | 34.60 | -9 |
| 24 | Christchurch East | DALZIEL, Lianne | 31.54 | -12 |
Lianne Dalziel and Clayton Cosgrove both dropped down the rankings in their Christchurch electorates, on the back of National's positive policy for rebuilding Christchurch.
Labour Party Vote by Electorate – Full Results
| Rank | Electorate | Candidate | Party (%) | Change |
| 38 | Auckland Central | ARDERN, Jacinda | 26.18 | -2 |
| 69 | Bay of Plenty | DEVOY-HEENA, Carol | 13.34 | -2 |
| 46 | Botany | WU, Chao-Fu | 23.51 | +10 |
| 29 | Christchurch Central | BURNS, Brendon | 29.01 | -3 |
| 24 | Christchurch East | DALZIEL, Lianne | 31.54 | -12 |
| 61 | Clutha-Southland | LOO, Tat | 16.15 | -3 |
| 56 | Coromandel | KININMONTH, Hugh | 17.91 | -2 |
| 20 | Dunedin North | CLARK, David | 34.49 | -7 |
| 17 | Dunedin South | CURRAN, Clare | 35.02 | -8 |
| 44 | East Coast | MACKEY, Moana | 23.67 | -3 |
| 58 | East Coast Bays | GOLDSMITH, Vivienne | 17.04 | +4 |
| 66 | Epsom | PARKER, David | 15.28 | +2 |
| 42 | Hamilton East | ORGAD, Sehai | 24.38 | +2 |
| 28 | Hamilton West | MORONEY, Sue | 29.05 | +3 |
| 5 | Hauraki-Waikato | MAHUTA, Nanaia | 46.49 | -1 |
| 68 | Helensville | GREENBROOK-HELD, Piers Jeremy | 13.88 | +2 |
| 65 | Hunua | HILLS, Richard | 15.45 | +4 |
| 16 | Hutt South | MALLARD, Trevor | 35.25 | -1 |
| 4 | Ikaroa-Rawhiti | HOROMIA, Parekura | 49.53 | -1 |
| 54 | Ilam | PARSONS, John | 19.07 | -1 |
| 30 | Invercargill | SOPER, Lesley | 28.71 | n/c |
| 53 | Kaikoura | COLLYNS, Liz | 19.88 | -2 |
| 11 | Mana | FAAFOI, Kris | 37.38 | +3 |
| 1 | Mangere | SIO, Sua William | 71.21 | n/c |
| 2 | Manukau East | ROBERTSON, Ross | 65.56 | n/c |
| 3 | Manurewa | WALL, Louisa | 55.85 | +2 |
| 13 | Maungakiekie | BEAUMONT, Carol | 36.78 | +12 |
| 12 | Mt Albert | SHEARER, David | 37.34 | +6 |
| 6 | Mt Roskill | GOFF, Phil | 43.16 | +11 |
| 27 | Napier | NASH, Stuart | 29.16 | +5 |
| 32 | Nelson | STREET, Maryan | 27.50 | -5 |
| 15 | New Lynn | CUNLIFFE, David | 36.34 | +7 |
| 40 | New Plymouth | LITTLE, Andrew | 25.62 | +2 |
| 60 | North Shore | CLARK, Ben | 16.24 | +3 |
| 41 | Northcote | GILLON, Paula | 24.80 | +6 |
| 57 | Northland | STEWART, Lynette | 17.18 | n/c |
| 37 | Ohariu | CHAUVEL, Charles | 26.32 | +2 |
| 26 | Otaki | FOSTER, Peter | 29.39 | +3 |
| 55 | Pakuranga | KAUSHAL, Sunny | 18.32 | +6 |
| 22 | Palmerston North | LEES-GALLOWAY, Iain | 33.75 | -1 |
| 39 | Papakura | MIKA, Jerome | 26.10 | +9 |
| 31 | Port Hills | DYSON, Ruth | 27.69 | -3 |
| 35 | Rangitata | BLANCHARD, Julian | 27.07 | -1 |
| 50 | Rangitikei | PAGANI, Josie | 20.89 | +2 |
| 23 | Rimutaka | HIPKINS, Chris | 32.92 | -3 |
| 70 | Rodney | ROSE, Christine | 13.23 | -4 |
| 21 | Rongotai | KING, Annette | 34.31 | -5 |
| 48 | Rotorua | CHADWICK, Steve | 21.64 | -2 |
| 62 | Selwyn | McLEAN, Jo | 16.02 | -7 |
| 59 | Tamaki | BAKULICH, Nick Iusitini | 16.98 | +6 |
| 8 | Tamaki Makaurau | JONES, Shane | 41.35 | -1 |
| 64 | Taranaki-King Country | BARKER, Rick | 15.59 | n/c |
| 52 | Taupo | CAMPBELL, Frances | 20.02 | -3 |
| 67 | Tauranga | MAHUTA-COYLE, Deborah | 14.60 | -8 |
| 10 | Te Atatu | TWYFORD, Phil | 37.98 | +9 |
| 7 | Te Tai Hauauru | PEKE-MASON, Soraya Waiata | 42.36 | -1 |
| 19 | Te Tai Tokerau | DAVIS, Kelvin | 34.60 | -9 |
| 9 | Te Tai Tonga | TIRIKATENE, Rino | 38.88 | -1 |
| 43 | Tukituki | HAYDON-CARR, Julia | 23.77 | -3 |
| 18 | Waiariki | TE KANI, Louis | 34.80 | -7 |
| 63 | Waikato | SUTTON, Kate | 16.01 | -3 |
| 45 | Waimakariri | COSGROVE, Clayton | 23.53 | -8 |
| 47 | Wairarapa | BOTT, Michael | 23.14 | -4 |
| 14 | Waitakere | SEPULONI, Carmel | 36.47 | +10 |
| 49 | Waitaki | MONKS, Barry | 21.60 | -4 |
| 36 | Wellington Central | ROBERTSON, Grant | 26.51 | -1 |
| 33 | West Coast-Tasman | O'CONNOR, Damien | 27.43 | +5 |
| 34 | Whanganui | McDOUALL, Hamish | 27.33 | -1 |
| 51 | Whangarei | NEWMAN, Pat | 20.12 | -1 |
| 25 | Wigram | WOODS, Megan | 30.67 | -2 |