Australia should be republic after Queen Elizabeth: PM Malcolm Turnbull

Australian Prime Minister Malcolm Turnbull has renewed his call for a republic, but only after Queen Elizabeth II's reign, as he outlined a road map for breaking away from the British monarchy.

Turnbull -- a staunch republican who led the cause before a failed referendum in 1999 -- said his support for an Australian head of state stemmed from patriotism.

"The cause of the Australian Republican Movement (ARM) is a cause for Australia," Turnbull said during a keynote address to the ARM yesterday.

"We do not diminish or disrespect the patriotism of those who take a different view, but we have no other motive, no other reason than love of country."

The British crown's power in Australia is seen as largely symbolic, and while the Queen is hugely popular Down Under, the monarchy is viewed by some as an anachronistic colonial relic.

Critics within Turnbull's own conservative Liberal Party earlier in the week said his support for a republic would be damaging to the government.

But Turnbull said there was no appetite among Australians for another referendum during Queen Elizabeth's reign.

"The less party political the republican movement is, the broader its base, the deeper its grassroots, the better positioned it will be when the issue becomes truly salient again," the Australian leader added.

Opposition Labor leader Bill Shorten appeared to criticise Turnbull's lack of action on Twitter following the speech.

"Climate change, marriage equality, housing affordability, now Republic too hard for Turnbull. Time for the PM to lead his party, not follow," Shorten tweeted.

He also offered to "work together to deliver an Australian head of state".

Support for a republic has wavered over the years, with a Fairfax-Nielsen poll in 2014 finding that 51 percent of the 1,400 people surveyed favoured the status quo compared to 42 percent supporting a republic.

Turnbull said question marks about how an Australian head of state would be elected -- directly by the people or via a parliamentary appointment -- had weakened support for a republic during the 1999 referendum.

He called for a two-stage voting process, with a plebiscite to determine the election model first before a referendum to decide on whether Australia should be a republic.

"We need to ensure that the Australian people feel they have chosen the model to be presented," Turnbull said.

"Of course every member of the parliament is elected, but we cannot be blind to the levels of cynicism about politics, parliaments and governments. If anything they are greater today than they were back in 1999.