Brisbane witnessed on Thursday two major players in Australia’s emerging republican debate agreeing to support each other’s model for a future Australian republic if their model is rejected by voters.

That is a change to the position in 1999, when frustrated Australians first voted "No" to an Australian republic as the different sides argued.

The Australian Republican Movement’s chair, Peter FitzSimons, and the Real Republic chair, David Muir – with different models for an Australian republic – vowed to support whichever model was supported by the Australian people.

The ARM’s “minimal change” approach favoured a model similar to the way an Australian Governor-General was chosen, effectively by two-thirds of the Australian Parliament.

The Real Republic members preferred that the head of state was directly voted on by Australians after a committee of well-credentialled Australians chose a number of applicants.

Mr FitzSimons agreed to back the direct-election model if the ARM’s model was rejected by Australians.

“I absolutely commit that, if minimalism does not get up, I will put whatever weight I have behind you,” Mr FitzSimons said.

Mr Muir said he could not spend the Real Republic’s $2 million direct-election campaign fund on a different model for a republic because Brisbane’s former lord mayor Clem Jones bequeathed the money for a direct-election republican campaign.

However, he agreed the Real Republic would publicly support the ARM model if the Australian people voted for that model instead.

“I can’t spend Clem’s money against his wishes, but I would think that most republicans, including us, would say that the Australian people have spoken and this is the model we want, let’s support it,” Mr Muir said.

This is the system in Ireland, where its head of state, currently Professor Michael Higgins, was directly elected by the Irish people.

Both agreed it was time for an Australian republic with an Australian head of state, with Mr FitzSimons' colourful language drawing laughs.

He used an example of 25 Australians photographed around an Australian barbecue compared with a recent photograph of the royal family on their balcony at Buckingham Palace.

“The youngest person on that balcony with Queen Elizabeth — only two weeks old — is automatically more qualified to be the head of state of Australia than anybody in your family,” he said.

“And your niece (let’s say) Esmerelda could win the Oscar by the age of 18, she could cure cancer by the age of 25, she could give us peace in the Middle East by the age of 35, rid us of Pauline Hanson by the age of 40.

“She could do all of these things and be the most accomplished Australian who has ever lived and under our constitution she would still be judged not good enough to be the Australian head of state."

A referendum on an Australian republic could be held in the first term of a new Australian government, possibly in 2019, after support from Opposition Leader Bill Shorten.

If Malcolm Turnbull’s coalition won the next federal election, a referendum on a republic would be held after the passing of the Queen.

Mr FitzSimons, the red-bandana-clad former Wallaby and Fairfax Media columnist, told a small crowd at QUT the ARM would prefer to thank Queen Elizabeth II during her lifetime for her excellent service to Australia, as a new republic came into force.

“She could come to the Opera House on a sparkling spring morning and instead of us bowing and scraping, we rise as one and give her a thunderous standing ovation,” he said.

“We say from the bottom of our heart, ‘Thank you, Your Majesty, for the sterling service you have rendered our nation.’

“She hands us the keys to the new constitution. We take it for a burn around the block and then say we’ll buy it and give her a lift to the airport.”

Mr Muir said Australians would first need a vote to sever ties with Britain.

After that, in a two-stage step, Australians would choose either for either two-thirds of parliament, or for the Australian people to elect their new head of state.

“And then, you will have a situation where the republicans will be united by the answers to those plebiscites,” Mr Muir said.

“So you won’t have that split as you did in 1999,” he said.

“So that is the key. We must allow the Australian people to choose the model."

Meanwhile, 18-year-old Ella Beutner, a member of Queensland University’s Republic Club for two years, said the club now had 150 members.

“I think it is not as if they do not want to be involved before, I think they just don’t know about it, to be honest,” she said.

“There was this period where we didn’t speak about a republic and it is really only in the last few years that it has come to the public attention again.”