Prime Minister Malcolm Turnbull has warned that he has no interest in leading the republican cause to another "heroic defeat", after Australian of the Year David Morrison helped thrust the issue back on to the national agenda. 
General Morrison, the former army chief, has vowed to make pushing for a republic one of his priority issues during his tenure as Australian of the Year.
"With great respect to those who don't share my views and recognising our proud history of European settlement in this country and beyond, over 200 years and more, I will lend my voice to the republican movement in this country," General Morrison said in his acceptance speech on Monday.
"It is time, I think, to at least revisit the question so that we can stand both free and fully independent amongst the community of nations."
General Morrison's comments came only hours after the Australian Republican Movement released a pledge, which was signed by eight of the nine premiers and chief ministers, calling for an Australian head of state.
Mr Turnbull, who led the republican movement to an unsuccessful result at the 1999 referendum, said on Thursday that the timing for any referendum would be crucial.
"I have led a 'Yes' case for a republic into a heroic defeat once - I have no desire to do so again," he said. "If you really are committed to Australia becoming a republic, then you want to be sure that the manner and the timing of the referendum is as such that it is successful and that it unites rather than divides Australians."
Mr Turnbull said a referendum would fail if it was seen to be politically driven. He repeated his long-held view that success would only follow the death of the Queen.
"To get momentum - and frankly there was more momentum in the late '90s than there is now - it needs to have grassroots support," he said.
Opposition Leader Bill Shorten called on Mr Turnbull to "shed the ghosts of the past generation" and work with him on advancing Australia towards a republic.
"I have no doubt - just as we should have constitutional recognition of our first Australians - that at 228 years on we are ready to have an Australian head of state," Mr Shorten said.
"We cannot leave the debate until another time."
General Morrison, who led the army from   June 2011 to   May 2015, has been a member of the Australian Republican Movement for about five months.
Australian Republican Movement chairman Peter FitzSimons said General Morrison would be a "boon" for the republican cause this year.
"I was doing cartwheels - it was just fantastic," Mr FitzSimons said of his appointment. "It is great to call him one of our own."
Mr FitzSimons said General Morrison was the type of person Australians would be proud to have as their head of state.
"He would make an outstanding president or governor-general," Mr FitzSimons said.
"I deeply admire him and the great service he has given our country."