The Green Party's housing spokesperson says landlords are crying "crocodile tears" after a year of amazing capital gains and falling mortgage interest rates.
The government this week announced its plans to help first-home buyers into the market, by increasing the caps for financial support, and extending the bright-line test to 10 years.
Green Party MP Chlöe Swarbrick said following the announcement the loudest voice in the room has been the concerns of investors, rather than renters and sole homeowners.
She said there's a narrative focusing on "mum and dad homeowners" but a large portion of the country's homes are owned by people who have a portfolio of properties.
"Thirty percent of the homes in this country are owned by people who own between four and more than 20 homes," Swarbrick said.
"Investors and landlords have had a halving of mortgage interest rates and a 25 percent increase in capital gains over the past 12 months, yet still found an excuse to raise rents."
Real estate agents have said the announcement was causing angst and confusion amongst property investors, with some dropping listings or trying to rush sales through.
Auckland investor and developer David Whitburn told Morning Report this week investors relying on rental incomes in their retirement are being unfairly penalised by the changes.
Swarbrick said less than a third of New Zealand houses are owned by people who only own one house.
"What we should be worried about is the inequality here, and the disproportionality that we are putting on hearing and listening to the kind of crocodile tears of property investors who have had the best circumstances financially and economically in the [last] 12 months ... you have had some of the most generous and fertile circumstances towards landlords than we have seen in a very long time, and they have still found the excuse to raise rents.
"My concern is actually not just just mums and dads around the country, but mum and dad renters particularly those who are older and are consistently being locked out of the market."
She said a "deficiency" of the government announcement did not include any new buildings, particularly new supply of public housing.
Rent controls are something that should be discussed, she said.