The Green Party will contest the Mt Albert byelection - a decision that will likely result in Green MP Julie Anne Genter going up against Labour's Jacinda Ardern.
Green Party Co-leader Metiria Turei said that Ardern, if selected to stand for Labour as expected, would be the favourite to win and a "very strong" candidate.
"The people of Mt Albert deserve to hear more than just one view on the issues they care about - that is their democratic right.
"It was weak of Bill English to opt out of running a National Party candidate in Mt Albert. He's denied thousands of Aucklanders the chance to engage with the government on whether they're ever going to fix the city's traffic-clogged roads, or finally put first-time homebuyers before property speculators."
There are a large number of Green voters in the Auckland electorate - 22 per cent of voters in Mt Albert gave their party vote to the Greens in 2014, about double the national result.
The Green Party candidate will be selected early in the New Year. The party's Auckland-based MP Julie Anne Genter has said she will put him name forward.
The byelection will be held on Saturday February 25. It is being held after David Shearer quit Parliament to head the UN mission in South Sudan.
National will not put up a candidate, with English saying the seat is a safe one for Labour and his party wants to focus on the general election.
That decision comes after National candidate Parmjeet Parmar lost heavily to Labour's Michael Wood in the Mt Roskill byelection this month.
The Green Party did not stand in that byelection, a decision reached after Labour and the Greens signed a Memorandum of Understanding, with the aim of changing the Government.
Mt Albert was won in 2014 by Shearer with a majority of 10,656.
National got 14,360 party votes in the seat in 2014, ahead of Labour on 10,823 and the Green Party at 8005.
Labour's 2017 campaign manager, Andrew Kirton, said his party was "relaxed" about the Green's decision to stand in Mt Albert.
"We're relaxed because Labour and the Greens share similar views about how the National government is failing Aucklanders.
"Labour will be taking nothing for granted and intends to earn a new mandate for our Mt Albert candidate by talking to the local community and focussing on how a Labour-led government can build a better New Zealand."
Nominations for Labour's candidate to contest the Mt Albert by-election close on January 12.
Shearer's resignation will take effect at the end of December and his new role as the head of the UN Mission in South Sudan will begin in January.
Ardern is a list MP and a win in Mt Albert means another Labour List MP will come into Parliament. Next on the list are Maryan Street and Moana Mackey, but Labour leader Andrew Little is understood to be keen to get Raymond Huo in to provide Chinese representation.
Ardern recently moved into Mt Albert with her partner Clark Gayford but had been intending to stand in Auckland Central for the third time prior to Shearer's resignation.
Ardern's shift to Mt Albert will open up the candidacy for Auckland Central, which Ardern was hoping to win from National's Nikki Kaye on her third attempt.
National stood its List MP Melissa Lee in the Mt Albert byelection in 2009 after Helen Clark left. Then a rookie MP, she had blotted her copy book by saying the Waterview connection motorway would have the effect of diverting South Auckland criminals out of Mt Albert. She later apologised.