The appointment of Australia's first woman Governor-General, who represents the Queen, has sparked speculation Australia might become a republic and break from Britain in five years.

Australians rejected a 1999 vote on becoming a republic and while there remains overwhelming liking for the Queen, around 70 percent of Australians favour the country becoming a republic, according to surveys.

Australian Prime Minister Kevin Rudd, a republican, announced on Sunday that Quentin Bryce, a state governor and a former sex discrimination commissioner, would be Governor-General in September.

"Will QB (Quentin Bryce) be the final Governor-General to see off QE (Queen Elizabeth), and her heirs and successors," asked the mass-selling Herald Sun newspaper in Melbourne. "In short, will our first female GG be our last?"

"Having made this historic choice, Mr Rudd has given himself a five-year window to work out a way of finding a way to devise an acceptable system to the people," it said on Monday.

Rudd as prime minister is Australia's head of government, but formally reports on many matters to the Queen's representative. The governor-general's role is largely symbolic, but does have little-used powers and former holder John Kerr sacked Labor Prime Minister Gough Whitlam during a 1975 constitutional crisis and replaced him with conservative opponent Malcolm Fraser.

Rudd, prior to meeting the Queen last week in London, said he was sure Australia would become a republic, but it was "not a top order priority" for his Labor government, elected last November.

"I would fully look forward to there being a spirited animated debate during the course of this year and beyond on our future Constitutional arrangements and that includes the republic," Rudd told Australian radio on Monday.

Former prime minister John Howard, a monarchist, engineered a 1999 republic vote which split the country three ways between support for the Queen as head-of-state, a popularly-elected president or a head-of-state chosen by the parliament.

Most Australians support a directly-elected presidency and rejected the model of one chosen by lawmakers, preferring to keep the current system of government.

"If the government holds to its current policy, a referendum could happen within the second term of a Rudd government," said Terry Fewtrell, the national deputy-chairman of the Australian Republican Movement, said.

A weekend Taverner poll in the Sun-Herald newspaper said 69 percent of respondents wanted the country to become a republic either as soon as possible, or when the Queen leaves the throne.

The Australian newspaper said Bryce, 65, whose appointment won near-unanimous support, was herself probably a republican at heart, having already backed a change of Australia's national flag, which incorporates Britain's flag.

"When appointed Queensland Governor in 2003, she said she had great admiration for the monarchy, which is about the minimum required of the Queen's representative," wrote The Australian columnist Mike Steketee.