Kevin Rudd, the charismatic prime minister once deposed by his own party, has never given up hope of capping an extraordinary political comeback with a second election victory, but he faces an uphill battle.
Rudd, 55, has campaigned hard for centre-left Labor to win on Saturday, having seemingly forgiven the party for cutting him down mid-term in 2010 -- a fate that reduced him to tears and stunned the nation.
Three years later -- after stints as foreign minister and a humble backbencher -- he re-emerged as the man who could potentially save Labor from a crushing electoral defeat and was sworn in as prime minister a second time.
He has refused to whitewash his unusual history, telling voters: "You've seen me at my highest highs and some of my lowest lows."
With the polls showing he is facing defeat, he has given no indication as to whether he will remain as opposition leader if he loses.
"This is politics. You take things one step at a time sign," he said on Saturday.
It was only in late June that the Mandarin-speaking ex-diplomat was sworn in as prime minister for a second time, after he ousted his former deputy Julia Gillard in a vote of Labor lawmakers.
Opinion polls had suggested Labor under Gillard would face catastrophic defeat in the election, and despite bitter divisions, the party chose Rudd to improve its chances.
In a bid to reunite the fractious Labor camp, since taking office Rudd has abandoned an unpopular carbon tax that Gillard had doggedly stuck to.
He has also announced a radical new plan to send boat-borne asylum-seekers to Papua New Guinea and Nauru, and deny them the right to settle in Australia even if they gain refugee status.
Rudd has also championed reforms to the Labor Party to make it harder to remove a leader.
Rudd stormed to power in 2007 with a landslide victory that ended a decade of conservative rule, campaigning for generational change with an emphasis on issues such as global warming.
He was for years a darling of the public, but his confidence with voters translated into egotism -- even megalomania -- behind the scenes, according to Labor colleagues who had, by mid-2010, lost faith in him.
A series of policy mis-steps gave party members the pretext to swoop, deposing him in a shock coup that delivered Gillard to power as Australia's first female leader. She kept him in the cabinet as foreign minister but they made uneasy partners.
Rudd came from humble beginnings -- a kid from the Queensland country, neither of whose parents went much beyond primary school -- to head the Labor Party and oust long-serving conservative leader John Howard.
As prime minister, he promised closer engagement with Asia, made a landmark apology to Australia's Aborigines for their treatment under white rule, and ratified the Kyoto Protocol on climate change.
The assured, bookish, leader kept Australia recession-free throughout the global financial crisis, an achievement that Rudd has hoped will keep him in office as the decade-long mining boom slows.
Rudd endured a tough childhood, forced to sleep temporarily in a car at the age of 11 when his family were evicted from their Queensland farm following his father's death in a road accident.
He has said that experience shaped the views on social justice that led him to run for federal parliament, where he was elected in 1998 at his second attempt.
Before arriving in Canberra he was a senior bureaucrat for the state Labor government in Queensland and had a lengthy career as a diplomat, including postings to Stockholm and Beijing.
The start of his first premiership's downfall can be traced to December 2009 when he failed to pass much-vaunted emissions trading laws and badly damaged his credibility with voters.
Rudd was further savaged in a public dust-up with the powerful mining industry over plans for a new tax on resources profits that finally sparked his ousting.
Despite his dumping, Rudd consistently came out in opinion polls as the preferred leader ahead of Gillard and it seems he never gave up on a political resurrection.
He is married with three children. His wife Therese Rein is a millionaire businesswoman.