It took just three hours on Wednesday morning for freshly minted New South Wales Premier Gladys Berejiklian's housing headache to become a full-blown migraine.

What is negative gearing? Negative gearing is a tax break incentive for property investors

Negative gearing is a tax break incentive for property investors It is a Federal Government issue, but State Governments often join the debate

It is a Federal Government issue, but State Governments often join the debate Some argue it hurts first-home buyers, who plan to be owner-occupiers

The policy reform many argue would help ease Sydney's affordability crisis — negative gearing — was the reason behind her pains.

About 7:30am, Ms Berejiklian told the ABC's Radio National she was reluctant to lobby the Federal Government on negative gearing because it was not to blame for the Harbour City's eye-watering house prices.

"I don't feel at this stage that is something I would necessarily touch in relation to housing affordability, because I think the first and biggest challenge in Sydney and New South Wales with housing affordability is still supply," she told presenter Fran Kelly.

But by 10:30am, the Premier's stance had softened considerably when she was needled over the issue at a press conference in Hurstville.

"I'm open to speaking to the Federal Government about options there," she said.

"I'm not ruling anything in or out on what is already Government policy today, and not just from bureaucrats — I want to seek advice from experts who have very strong views and also track records of dealing with this issue."

And if those experts say negative gearing needs reform?

"If there is overwhelming advice one way or another that there are issues outside of New South Wales Government control that need to be addressed, of course I'll raise that with the relevant authorities. That's my job."

Negative gearing in spotlight again

Negative gearing has been a hot topic in Australia's largest city, where the average house price hovers around an eye-watering $1 million.

The policy provides a tax break for investors, with many first-home buyers questioning the logic behind an incentive that helps people to buy their second, third or tenth properties.

In November, NSW Planning Minister Rob Stokes broke ranks with his Federal Liberal Party colleagues to complain that negative gearing should be changed to help make housing in Sydney more affordable.

Yesterday, a survey rated housing in the Harbour City as less affordable than global metropolises New York and London, and claimed Sydneysiders were paying "four times" too much for real estate.

Federal Labor's Shadow Treasurer Chris Bowen criticised the Turnbull Government for not doing enough to help first home buyers.

"Now it is time for this Government to actually act, instead of lecturing people, telling people to get a better job or get rich parents or move to Charleville, this Government should have a housing affordability policy," he said.