Australian Prime Minister Julia Gillard said on Sunday she was "very confident" of surviving a leadership challenge from Kevin Rudd the man she deposed calling on Labor to unite whatever the outcome.

Rudd, ousted as prime minister in a shock June 2010 party-room coup, will face Gillard in a secret Labor ballot for the leadership Monday after dramatically resigning as foreign minister in a bid for the top job.

Gillard said she was "very confident of the strong support of my colleagues" and called on her center-left ruling party to accept the decision and leave their divisions behind.

"I believe Labor, every one of us, will unite after Monday's ballot. We will unite tomorrow and we will get our shoulders to the wheel delivering Labor's program and plans," Gillard told reporters.

"The important thing is that tomorrow's ballot ends this there is a result and following that result everyone accepts it and unites and gets on with the job and I am absolutely confident that will happen."

Rudd came to power in a 2007 election landslide which ended more than a decade of conservative rule, but a series of policy mis-steps saw him lose the confidence of party chiefs and he was axed for the more pragmatic Gillard.

Though he is widely expected to lose Monday's run-off, with just 30-35 votes in the 103-member caucus, Rudd said he had the backing of a number of top cabinet ministers and urged his colleagues to remember his achievements.

He also pledged "unequivocal support" for Gillard were she to win the ballot.

"If Julia is returned on Monday then she will have my unequivocal support between now and the next election, because we have interests way beyond individuals here," Rudd told the Nine Network.

"This thing is bigger than all of us. If I get mowed down by a bus tomorrow political or physical the bottom line is this: the party and the government and the country is much bigger than me," he added.

Opposition leader Tony Abbott repeated his calls for the minority MPs who make up Labor's fragile coalition government to withdraw their support and force an election.

Abbott would not confirm whether he was planning to bring a no-confidence motion in parliament, saying only: "I think for Australia's sake this government should go."

Monday's vote caps a period of intense turmoil within Labor, brought to a head by Rudd's dramatic resignation as foreign minister in Washington on Wednesday and his subsequent decision to contest the leadership.

Australian Prime Minister Julia Gillard said on Sunday she was "very confident" of surviving a leadership challenge from Kevin Rudd the man she deposed calling on Labor to unite whatever the outcome.

Rudd, ousted as prime minister in a shock June 2010 party-room coup, will face Gillard in a secret Labor ballot for the leadership Monday after dramatically resigning as foreign minister in a bid for the top job.

Gillard said she was "very confident of the strong support of my colleagues" and called on her center-left ruling party to accept the decision and leave their divisions behind.

"I believe Labor, every one of us, will unite after Monday's ballot. We will unite tomorrow and we will get our shoulders to the wheel delivering Labor's program and plans," Gillard told reporters.

"The important thing is that tomorrow's ballot ends this there is a result and following that result everyone accepts it and unites and gets on with the job and I am absolutely confident that will happen."

Rudd came to power in a 2007 election landslide which ended more than a decade of conservative rule, but a series of policy mis-steps saw him lose the confidence of party chiefs and he was axed for the more pragmatic Gillard.

Though he is widely expected to lose Monday's run-off, with just 30-35 votes in the 103-member caucus, Rudd said he had the backing of a number of top cabinet ministers and urged his colleagues to remember his achievements.

He also pledged "unequivocal support" for Gillard were she to win the ballot.

"If Julia is returned on Monday then she will have my unequivocal support between now and the next election, because we have interests way beyond individuals here," Rudd told the Nine Network.

"This thing is bigger than all of us. If I get mowed down by a bus tomorrow political or physical the bottom line is this: the party and the government and the country is much bigger than me," he added.

Opposition leader Tony Abbott repeated his calls for the minority MPs who make up Labor's fragile coalition government to withdraw their support and force an election.

Abbott would not confirm whether he was planning to bring a no-confidence motion in parliament, saying only: "I think for Australia's sake this government should go."

Monday's vote caps a period of intense turmoil within Labor, brought to a head by Rudd's dramatic resignation as foreign minister in Washington on Wednesday and his subsequent decision to contest the leadership.