Kevin Rudd's chances for the top job at the United Nations have been dealt a blow by experts, who say there is a stronger candidate who ticks all the right boxes.
Bulgarian Irina Bokova, the current head of the UN's largest agency UNESCO, announced her candidacy for the post of secretary-general earlier this year.
International relations experts and Mr Rudd's brother Greg said on Friday Ms Bokova was viewed by many as the strongest contender to declare their interest in the post so far.
Greg Rudd told Fairfax radio station 3AW that he did not believe there was a possibility his brother could take over leadership of the United Nations when Secretary-General Ban Ki-Moon steps down on December 31, 2016.
"And it's got nothing to do with Kevin's ability, it's just the way the UN works," he said.
"The UN started in 1945, there have been eight secretary-generals, none have been women and none have come from the eastern European section.
"The general view, globally, is that it's their turn."
Experts said Ms Bokova was an extremely strong performer who met the UN stipulation of fluency in French.
Independent researcher Peter Nadin said Ms Bokova had the added advantage over Mr Rudd of experience leading a UN agency.
Dr Nadin said he believed Ms Bokova was a candidate who would have support from permanent UN Security Council members Russia and the United States.
That a woman has never been named secretary-general of the UN was a factor Dr Nadin said was also likely to strengthen former New Zealand prime minister Helen Clark as a candidate over Mr Rudd if Ms Clark sought the role.
"[Mr Rudd's] a statesman, a proven statesman, has foreign policy experience, he's currently based in New York at the Asia Society and I think he's doing some work at the International Peace Institute," he said.
"I think that those are the main things he has going for him.
"If you were going to look at things going against him he doesn't have any UN mission experience – he hasn't actually led a UN agency.
"Helen Clark is the current director of UNDP [United Nations Development Program] which counts in her favour again."
Russell Trood, the president of the United Nations Association of Australia and a professor of international relations at Griffith University, said Mr Rudd was "exceptionally qualified having been a prime minister … with an extensive reputation for experience in international relations and foreign policy".
"But often these jobs aren't necessarily to do with experience or competence," the former Liberal senator said.
"It's more about the problem of negotiating the politics of the almost byzantine process of the UN.
"It tends to be a matter of the P5, the five permanent members of the security council, who determine the outcome of the matter."
He said while Mr Rudd had a lot of strong credentials any candidate would also have to have the backing of the Australian government.
"Would the Australian government support his candidacy? I just don't know the answer to that," Professor Trood said.
In an interview with Fairfax Media Mr Rudd did not deny his interest in the job but said he took the "utterly pragmatic" view that it was Eastern Europe's turn at the leadership.
