Voters in the eastern suburbs of Christchurch head to the polls on Saturday to select a new MP after their last one became the city's mayor.
The Christchurch East seat has traditionally been a Labour strong-hold, but in the last election the party vote went to the National Party.
Polling booths open at 9am on Saturday and 10 candidates are vying for the seat left vacant when Labour's Lianne Dalziel resigned to successfully contest the mayoralty, replacing Bob Parker.
By late Friday afternoon, about 2700 voters had cast their ballot, compared with about 4000 at the same stage last election. Almost 29,000 people voted in the electorate last election - but the turnout on Saturday is expected to be much lower.
Labour Party candidate Poto Williams says she is quietly optimistic of winning and is the front-runner, but could face tough competition from National's Matthew Doocey and David Moorhouse from the Greens.
Ms Williams said on Friday she is making a final push to ensure her supporters get out and vote.
"A lot of people think that Labour tend to have it in the bag, it's been a safe Labour seat, we've held it for a hundred years. I've got to say categorically that's not the case. We might have a lot of support; we need to turn that support into votes."
National's Matthew Doocey said he is not losing hope over the by-election, despite Prime Minister John Key saying he is unlikely to win.
"We have to be realistic, this is a safe Labour seat. But you've got to go in, you've got to work hard, and people are saying they want a bit of new change and a new start, and I think I represent that," Mr Doocey said.
Green candidate David Moorhouse says he's confident he has won votes from Labour and National camps and believes he has a shot at winning.
"I'm quietly confident, I'm leaving it to the wisdom of the people in Christchurch East to choose the representative that's best for them - and they know that they need somebody that's got the eastern in his DNA."
Mr Moorhouse says he has put pressure on the candidates from the major parties to perform.
Leighton Baker Conservative Party; Matthew Doocey, National Party; Ian Gaskin, Independent; Adam Holland, Independent; Paula Lambert, Aotearoa Legalise Cannabis Party; Jenner Lichtwark, Democrats for Social Credit; David Moorhouse, Green Party; Sam Park, Independent; Gareth Veale, ACT Party and Poto Williams, Labour Party.