Dominic Perrottet argues three-year federal government terms force politicians into never-ending campaign mode, which complicates significant reform.

The treasurer made the remarks to a forum in Sydney working to redefine the Commonwealth's interaction with NSW.

Mr Perrottet took aim at the revolving door of leadership in Canberra, noting the country has had five changes in prime minister in 10 years.

"You don't need to be a professor of political science to know that if you can't keep a prime minister in the job for a full term - you can forget about reform for the long term," Mr Perrottet said on Monday.

As a result, the nation's capital was enduring what Mr Perrottet described as a "wasted decade ... of Canberra comatosis" - part comatose, part sclerosis.

"Because politics has become so consumed by day-to-day survival that we seem to have given up on governing for the long term," he said.

While the treasurer believes four-year federal terms would help stoke reform, he argues a change in attitude is also needed.

The federal financial relations review, which is due to publish its final report in the first half of 2020, has been tasked to deliver more sustainable funding arrangements and greater financial autonomy for NSW.

Former New Zealand prime minister Bill English, former Australian deputy prime minister John Anderson, professors Anne Twomey and John Freebairn, Commonwealth public servant Jane Halton and former Telstra chief executive David Thodey are overseeing the review.

Australian Associated Press