Bill Shorten is poised to commit to holding a national vote on becoming a republic with an Australian head of state within the first term of a future Labor government.

He will also promise to appoint a minister with direct responsibility for driving the debate, during a speech to the Australian Republican Movement in Melbourne on Saturday.

"If the yes vote prevails - and I'm optimistic it will - then we can consider how that head of state is chosen," the opposition leader will say.

Pitching his case for an Australian republic, Mr Shorten points to the federal politicians ensnared in an ongoing dual-citizenship saga for not renouncing allegiance to a foreign power.

However, laws enacted by parliament are passed in the name of someone who will never be an Australian citizen.

He also seizes on Malcolm Turnbull's recent calls for prospective Australians to "join us as patriots", arguing the British monarch can hardly be considered an Australian patriot let alone a loyal citizen.

Mr Shorten insists the republican debate is not about a lack of respect for the Queen, saying he has tremendous regard for her service.

But he urges against waiting for a change of monarch, arguing Australia ought not tip-toe around its future.

Queen Elizabeth II would farewell Australia with affection and good grace, the country could still compete at the Commonwealth Games and fawn over the royal babies.

Mr Shorten says enshrining a voice for indigenous Australians is the first priority for constitutional change and can be achieved in this term of parliament.

It will then be time to give new generations, including millions of migrants and those born after 1999, the chance to shape Australia's future.

"I know an Australian republic isn't front of mind for everybody, but I don't buy the argument that we can't have this debate until every other problem in the nation has been solved," he will say.

Mr Shorten will caution against holding a referendum akin to that which failed in 1999, where Australians were given one vote to settle two questions.

He believes many voted "no" because of the model, not the republic.

He will argue the first clear question asked should be whether people want an Australian head of state.

"And the debate should be about why. About our sense of Australia, our history and above all, our future."