Any push for Australia to formally become a republic would be a "slow burn": PM

Australian Prime Minister Malcolm Turnbull has again thrown his support behind the Australian Republican Movement (ARM), but has acknowledged it was unlikely to occur until after Queen Elizabeth II's reign.

Speaking at the group's 25th anniversary dinner overnight, Turnbull, who was head of the republican movement from 1993 to 1999 including the group's failed 1999 vote, said Australians would be unlikely to back the push while the Queen is still ruling, but did not rule out a vote in the near future.

"I do not believe Australia would welcome, let alone support, another public referendum during her (Queen Elizabeth II's) reign," Turnbull said on Saturday night.

He said any push for Australia to formally become a republic would be a "slow burn," which must be thought out and embraced by all Australians regardless of how they vote.

"We would need to have an advisory plebiscite which would offer a choice between two republican models, presumably direct election and parliamentary appointment," he said.

Turnbull's comments came a day after the current head of the ARM, Peter FitzSimons, said for the first time, there was majority support in the parliament for an Australian republic.

Following Turnbull's cautious approach to the subject on Saturday night, FitzSimons acknowledged the challenge ahead for the group.

"He's the prime minister - he's experienced in this field and he's saying make no mistake you have a long hill to climb," FitzSimons said.

"The point that I'm about to make in return is ... we are climbing that hill, we've got extraordinary enthusiasm."

The plan has also received backing from the nation's opposition leader, Bill Shorten.

He posted to social media: "My offer still stands - let's work together to deliver an Australian head of state."

In 1999, Australia narrowly voted against leaving the British monarchy to become a republic. Endit