The government's being warned off even contemplating capping rent increases, saying that would be a further devastating blow to property investors.
The impact on rents is just one of the topics that continues to be hotly debated, following last week's announcement of a package aimed at cooling the housing market.
Property investors - who say they feel under attack - are predicting rent hikes could soon follow.
In response, the Finance Minister Grant Robertson said the government will keep a watching brief on rent prices, and would take action if needed.
But the Prime Minister has hosed down any suggestion of rent controls.
Here's our political editor, Jane Patterson.