The Green Party is urging the Government to keep rent control on the table, as many renters find themselves stretched to their financial limit.
Newly released documents show Housing Minister Megan Woods sought advice from officials late last year on the potential effects of temporary rent controls alongside its sweeping housing package.
But earlier this month, Associate Housing Minister Poto Williams poured cold water on the prospect of such measures, saying she had "no further plans" in that area.
Green MP Chlöe Swarbrick said ministers must not rule out rent controls before the public had a chance to debate the matter.
"We should not be taking this off the table," she told RNZ. "We are very much keeping this conversation alive."
Swarbrick said the Greens had long advocated for renters' rights and would have "more to say" on possible controls in the near future.
"For far too long, a very select number of people have been able to control the dialogue of what is politically possible in the country.
"And that has resulted in outcomes that are not working well for the third of this country that rent."
Screeds of documents, published yesterday, show ministry officials warned the Government that its suite of housing policies, announced last month, could hurt vulnerable renters.
In a Housing and Urban Development Ministry paper prepared for Woods in December, officials said they believed "most landlords" might consider increasing rent.
Officials noted it was unlikely investors would pass all the increased costs on to tenants, but only because "stressed renters" could not afford to pay much more.
Renters could, in turn, end up sharing housing costs and crowding into smaller homes. If landlords chose to sell up, low-income renters could be turfed out and hit with moving costs, the paper warned.
"There is a risk that for some renters in the lower-priced parts of the rental market, they will not be able to find a new rental property at a price they can afford.
"This could lead to either further pressure on emergency special needs grants, transitional and public housing, or to overcrowding to enable rent to be affordable."
A Cabinet paper created by the Finance Minister in February noted that the likely impact on rents were "complex and uncertain", but any upward pressure would disproportionately hurt Māori and Pacific people as they are less likely to own their home than other ethnic groups.
"Major reforms of the structural underpinnings of the housing system may result in near-term adverse consequences for some vulnerable groups.
"Following these reforms, the Ministry of Housing and Urban Development will monitor market impacts closely, including on the rental market, to assess whether further interventions may be necessary."
The paper noted that ministers would direct officials to consult on a proposal to limit rent increases to once every 12 months per property, instead of per tenancy.
Swarbrick said property owners had massively benefited from plunging interest rates and eye-watering capital gains over the past year.
"Landlords have had an incredibly good run of it... and yet have still found excuses to put up rent."
Think tank New Zealand Initiative on Thursday published a document arguing that rent controls would make the crisis worse.
Senior fellow Dr David Law told Morning Report such measures invariably reduced the supply of rental accommodation as investors sold their properties or left them empty.
"There are inequality issues. It tends to be the case that higher-income people end up benefiting the most from rent controls. It reduces mobility, people don't move for jobs when they should."
Swarbrick said it was bizarre to characterise reduced transience as a negative when most people valued a greater "sense of security and stability".
"There are a number of different variables and ways in which you could set up a system around what rent control could look like."