New Australian PM Rudd urges 'gentler' politics

Kevin Rudd called for a "kinder, gentler" approach to politics Thursday after being sworn in as Australia's new prime minister almost three years to the day since he was ruthlessly ousted from the job by Julia Gillard.

The 55-year-old sealed his dramatic return after a leadership ballot on Wednesday, in which Gillard, the country's first female premier, was deposed in a party-room vote and announced her retirement from politics.

With Labor desperately fighting for electoral survival, Rudd used his first speech to parliament since seizing back power to acknowledge that politics could be brutal.

"Political life is a very hard life, a very hard life indeed," he said. "Occasionally it can be kind, more often it is not."

He asked MPs to "be a little kinder and a gentler with each other in the further deliberations of this parliament" while praising Gillard.

"Through the difficult years of minority government the former prime minister has achieved major reforms for our nation that will shape our country's future," he said.

"On top of all that, I acknowledge her great work as a standard-bearer for women in our country."

Rudd's resurrection marks a stunning turnaround for the former premier who will now lead Labor to elections scheduled for September 14, which polls predict Tony Abbott's conservative opposition will win by a landslide.

Six key ministers resigned in the aftermath of Gillard's dumping, including her most loyal supporter, Treasurer and deputy leader Wayne Swan.

On Thursday, Gillard's Transport Minister Anthony Albanese was sworn in as Rudd's deputy while former Immigration Minister Chris Bowen was appointed treasurer.

Labor's popularity has tanked under Gillard but Rudd, who ended a decade of conservative rule with a comprehensive 2007 election win, remains popular with voters and his elevation is expected to give the party a significant boost.

John Wanna, a politics professor at the Australian National University, said Rudd could help reverse the slide.

"His message is much better than Gillard's, that's been very clear. He's a populist." he said.

Analysts are tipping Rudd will bring the election forward to August 24 in order to capitalise on an expected surge in Labor's popularity, although Albanese said a "proper discussion" was needed first.

Gillard called Wednesday's leadership ballot after a day of internal party manoeuvring in favour of her arch-rival.

Rudd won the vote of Labor lawmakers 57 to 45 -- the third time since the 2010 election that embattled Gillard's hold on power was tested.

The charismatic Rudd himself launched an unsuccessful challenge in early 2012 while foreign minister, but was routed 71 votes to 31 and was forced onto the backbenches.

Then in March this year, Labor elder statesman Simon Crean made an abortive attempt to reinstall Rudd, who refused and vowed never to challenge Gillard again.

In his pre-caucus pitch Wednesday Rudd said that he could no longer stand by and watch Abbott elected to office.

He promised a better relationship with the business community and appealed to younger voters, with his return expected to see Abbott reset his campaign approach for a more popular opponent.

Abbott Thursday slammed three years of "back-room deals and backstabbing" within Labor ranks and suggested Rudd was more interested in ego than the Australian people.

"Yes, he's had his revenge, but is this all about Kevin Rudd's ego or is it about the Australian people?" he said on Fairfax radio.

The conservative leader had few compliments about Gillard, who famously accused him of a being a misogynist and will sit on the backbenches until retiring at the election.

"I have a feeling that history will judge her pretty harshly because I think it was a poor prime ministership," he said.

Gillard expressed pride in her concession speech at being the country's first female leader, who often battled sexist attacks and slights on her gender.

"What I am absolutely confident of is it will be easier for the next woman and the woman after that and the woman after that. And I'm proud of that," she said.