"I am still undertaking that work. But what I've also heard from New Zealanders is that they also want that certainty.
"We have found the balance between both. We will do the work, but we will make sure that it doesn't take effect until after New Zealanders have seen the final complexion."
Early voting opened on Monday, and Labour's about-turn on tax came after 150,000 people had already cast a vote.
Ardern was asked what she would say early voters who thought Labour would bring in tax changes next term.
"I always maintained that I would undertake the work," she said.
"I also indicated that it would take us some time to do it. It would only be in effect a short time after the next election.
"My message to those voters is I'm still committed to it. There is urgency, I'm going to do the work that the Government hasn't done."
Labour still plans to extend the "bright line test" introduced by National from two years to five years. That would mean anyone who resold a house which was not the family home within five years would pay tax on the profits.
With eight days to go until election day, Ardern said there would be no change of tack from her party. Labour would spend the final week of campaigning focusing on housing, health and environmental issues.
"After so much drift, we just have so much risk still in the system if we do not change government," Ardern said.
"There is a real risk sticking with the status quo. That will be our message."
Ardern spent her time in Dunedin talking to residents who were affected by floods in 2015.
She said central government needed to work more closely with local government to adapt and mitigate the effects of climate change, such as sea level rise.
"This is not an issue that local government can deal with alone."
Ardern was uncertain about whether climate change was a vote-winner.
"For some people, it will [be]. Regardless of whether or not it triggers people to vote, actually we've got a responsibility, a duty of care to people in these communities to make sure that we're doing out bit."
Labour released its climate-change policy on Friday, which included a commitment to make New Zealand carbon-neutral by 2050.