Labour has pledged to make a $1.36 billion light rail service from Mt Roskill to Auckland's CBD a priority, if it is elected to government.
Auckland Council's proposed 13km light rail system would run from Wynyard Quater to Britomart, along Queen Street, Dominion Road and end in Mount Roskill.
The new line would intersect with bus and heavy rail networks at several stops to make it accessible to more people.
Labour leader Andrew Little said the estimated $1.36 billion network would help tackle the city's worsening congestion problems.
The project would be spilt between central government and the council.
He said 29,000 people lived within 500 metres of the planned stops, and 48,000 jobs were located there.
"Right now gridlock is choking Auckland's ability to grow, Auckland is crying out for innovative infrastructure projects to get the city moving.
"The government in out of touch and ignoring the problem, Labour will deliver starting with the modern light rail line," Mr Little said.
He said Auckland Council wanted to build light rail from Mount Roskill to the CBD within 10 years, but National had refused to commit to funding.
"The council had it as part of its 2016-2026 10-year plan, but the government's Auckland Transport Alignment Plan has pushed it back to after 2028 despite acknowledging that passenger demand requires it within the coming decade.
"We want to work with the council to make this project a priority within the next 10 years.
"It will cut travel times, reduce congestion and pollution and boost productivity.
Mr Little said the investment would make a big difference to Auckland's future.
Labour announcement a 'flip-flop' - National
However, the National Party candidate for the Mount Roskill by-election, Parmjeet Parmar, said the announcement was a shameless "flip-flop".
Dr Parmar said fixing the current infrastructure, such as bus stops and footpaths, was more important than billion dollar plans that would take a decade.
The light rail system was on National's list, just not within the next 10 years, she said.
"My opponent [in the Mount Roskill by-election, Michael Wood] is doing a huge flip-flop here, he himself said a year ago that 'we need to do more homework on this'.
"But as soon as Mayor Phil Goff announced his Auckland Transport policy, he just changed his position," Dr Parmar said.