A number of Queen's birthday honours recipients have come out in support of an Australian republic after being presented with their award, including 2010 Australian of the Year Patrick McGorry.
Prof McGorry said the present and future of Australia was not linked to the British Empire, but "an independent country that is mature enough to have its own head of state".
"What I don't understand is why politicians always say: `Well yes, it's an important issue but we're not ready for it yet, there are other important issues'," he told AAP.