The NSW government has told Andrew Barr to "focus on his own backyard rather than playing the political blame game", after he suggested the state's lack of spending on social housing had created extra demand for properties in the nation's capital.
NSW Housing Minister Melinda Pavey added that "unlike the ACT, NSW isn't play catch-up with delivering social housing".
Mr Barr last week accused the NSW government of a "chronic underinvestment" in social housing, as he and ACT Housing Minister Yvette Berry faced questions about the shortage of properties in the capital and the wider issue of support for low-income earners.
The ACT's Labor-Greens government considers itself a nation leader in public housing investment, headlined by a rolling 10-year program of renewing properties across the territory.
The program has a price tag of $1 billion, and will include construction of 400 new dwellings by 2025.
But housing advocates say the investment isn't enough given an estimated shortage of 3000 properties in the ACT.
At a press conference late last week, Mr Barr pointed the finger at the Berejiklian government.
"There is another government that sits just over the border that has a [public housing] waiting list of over 60,000 and a chronic underinvestment in its own public and social housing portfolio ... and that is NSW," Mr Barr said.
"We can do a lot here and we are, but we will never be able to provide housing for the ACT and most of NSW.
"We have to be frank about the reality that the government just over the border, and this region, needs more housing ... and it's not just the ACT government's responsibility to provide it."
The Canberra Times on Monday morning asked the offices of Mr Barr and Ms Berry to provide evidence to back up the chief minister's statement.
Neither had provided a response as of Wednesday night, despite repeated requests.
But Ms Pavey, who is a member of the Nationals, did offer a response, firing a political shot at Mr Barr while defending her own government's record on public housing investment.
"Supporting vulnerable people is a shared responsibility and Mr Barr needs to focus on his own backyard, rather than playing the political blame game," Ms Pavey said.
"Unlike the ACT, NSW isn't playing catch-up with delivering social housing."
Her office pointed to Productivity Commission data which showed NSW had, with the help of community housing providers, grown its social housing stock by 10 per cent in the past decade, compared to the ACT's one per cent.
Ms Pavey said the NSW government had increased its budget for social housing by more than 80 per cent this financial year.
The state's total housing portfolio was now worth $51 billion, up from $32 billion a decade ago.
"The NSW government for years has put in place a policy framework to not only deliver new and better social housing - but in a more most cost effective way," she said.