Extending federal electoral terms to four years is "not a priority" for the Federal Government, according to Treasurer Scott Morrison.

The proposal was floated by the Opposition Leader Bill Shorten on Sunday in an interview with the ABC's Insiders, prompting a phone call from Prime Minister Malcolm Turnbull to discuss the idea.

Currently federal terms are for three years, but the prime minister of the day has broad discretion as to when the election can be called.

Mr Shorten warned the current system was stifling reform and said governments would be "more daring and determined" if they were not constantly thinking about the next election.

But Mr Morrison said the change was not a top priority for the Turnbull Government.

"Bill [Shorten] raised this, he seems to be pushing it. The Prime Minister agreed to have a conversation about it," Mr Morrison told ABC RN.

Earlier this year, Liberal MP David Coleman introduced a draft bill for four-year terms, arguing it would make it easier for governments to implement long-term policies.

Health Minister Greg Hunt said the change was not a priority but that fixed terms could likely win public support.

"There is a good case for four-year terms to give us exactly the opportunity [former prime minister] John Howard referred to in a longer period to deal with the medium term and deep issues," he said.

'It's 6,000 days of governing time lost'

There are two issues at play when it comes to changing federal electoral cycles — extending the period from three to four years, and fixing the date at which terms expire.

Executive director of the Australia Institute, Ben Oquist, said the average term of a government since 1910 had been around two-and-a-half years.

He argued fixing the date of an election should be of greater significance.

"It's 6,000 days of governing time, if you like, lost," he told ABC News Breakfast.

"It's not because we haven't got four-year terms, it's because we haven't got three-year terms.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 7 minutes 10 seconds 7 m Constitutional law expert George Williams talks about Bill Shorten's proposal

"By fixing it at three years, we get ourselves a longer term — it'd be good for democracy, it would stop [the] prime minister being able to pick and choose election dates and manipulate election timing, it would be better for governing and we wouldn't waste so much about when an election's going to be."

Mr Oquist said fixing the length of terms was also a better option because it could be done without the need for a referendum.

Extended terms could improve stability in politics

ABC election analyst Antony Green said there had been a number of referendums to change electoral terms since Federation, which had been unsuccessful.

"The difficulty is that you've got to come up with a proposal here which deals with double dissolutions, deals with fixed terms, deals with tying the Houses together, and come up with a compromise," he said.

"I can't see it happening within a decade."

Constitutional expert George Williams from the University of New South Wales said extending parliamentary terms could lead to more stability in politics.

"I think here the argument is that maybe we're going to get better government with actually a period of time to develop policy and ideas in a way that doesn't often happy as it should at the moment," he told AM.