"We know it is important to get this right, so we will balance the need for certainty and urgency by ensuring that any potential changes will not come into effect until the 2021 tax year.
"This gives multiple opportunities for public input, and a general election before any new tax would come into effect.
"To avoid any doubt, no one will be affected by any tax changes arising from the outcomes of the Working Group until 2021.
"There will be no new taxes or levies introduced in our first term of government beyond those we have already announced."
Ardern said it was her "captain's call" to back down from introducing new taxes in a first term of a Labour Government because it was clear the public were concerned.
Ardern denied her decision was because National's attacks on the matter were damaging Labour in the polls, saying she accepted there was uncertainty about it and had listened to people.
"I have been driving our campaign and I have taken political risks but I've done that because I feel so strongly around the urgency there is around tackling the housing crisis. But I needed to also balance that against certainty for voters."
She said Labour would still legislate for new taxes in a first term - but they would not come into effect until 2021 - after a further election, which is also what National has done with its tax cuts.
"This is about making sure we are providing certainty to voters but also there is still real urgency around tackling the housing crisis. So I will continue to undertake this work in government but we have balanced that against the need for people to be certain when they vote around exactly what they will be doing."
Robertson said he thought New Zealanders would appreciate that the work on tax needed to be done to rebalance the tax system.
He would not say whether he expected the working group to address taxes on assets other than property but said the housing market was Labour's focus.
"We cannot sit around and let the housing crisis get worse and worse as National have done over the last nine years. We will do the work. We will make sure New Zealanders see it and if they don't want it, then they won't have to have it.
"We owe it to New Zealanders to make sure that they can get in, buy their first home, and make sure that our housing market is not part of the speculators' dream. We have to do something about that."
Labour has ruled out a capital gains tax applying to the family home or to the land under the family home. It has also ruled out an inheritance tax.
The move comes after the latest Newshub-Reid Research poll, showing National on the rise and Labour on the decline.
Labour has gone into the past two elections with detailed policy on introducing a capital gains tax.
Former leader Andrew Little changed that and said the party in government would set up a tax working group - but said that policy derived from it would be put to a mandate at the 2020 election.
Today's announcement effectively takes Labour back to Little's position.
The National Party has dismissed today's announcement and claims it is further proof that Labour can't be trusted on tax.
National's finance spokesman Steven Joyce said Labour's move had only postponed two new taxes, while leaving five in place that would slow down the economy and restrict growth.
"They've postponed the introduction of two taxes but have reaffirmed their intention to impose a water tax, regional fuel tax, tourism tax, income tax increases, and bringing farming into the ETS," he said.
This was Labour's "fifth version" of its tax policy in the past month and it was still "too vague on a whole range of policies and it shows".
Joyce said: "The public simply can't trust Labour on tax."
National Party leader Bill English told media in Gisborne that voters still faced uncertainty under Labour, and would have income tax cuts scrapped.
"It is not much of a walkback. As I understand it what they have done is postpone a couple of taxes - capital gains tax and land tax. You will still be voting for a committee who will decide that.
"Labour seem to want to do it but can't bring themselves to say so. The real issue is around the income taxes. The current law of New Zealand is that on April 1 someone on the average wage will be about $1000 a year better off. Labour will have to pass legislation in the Parliament to take back that $1000 a year."
Labour will instead introduce their own families package, which the party says will leave most families better off than under National's tax cuts.
But English said many Kiwis would be penalised, particularly those without children.
He said everything Labour had said about wanting to address speculation in the housing market "has turned out to be meaningless".
