effort to shore up support by the governing Labor Party, which opinion polls show faces catastrophic defeat at a poll scheduled for Sept 14.
The Mandarin-speaking former diplomat draws strong popular support but has divided and destabilised his party after launching two failed leadership bids in the past 18 months.
Analysts said the leadership change could backfire.
“I don’t think it will help Labor. I think they’ve dug themselves a deeper grave,” said John Wanna, professor of politics at the Australian National University.
The return of Rudd could now see Australia go to an election in August in an effort to cash in on his greater popularity with voters and an expected honeymoon period with the electorate.
Election timing unclear
Rudd, who was prime minister from late 2007 until June 2010, gave no indication of whether he would call an early election, or test his support on the floor of Australia’s hung parliament.
He also made no comment on when he would visit the governor-general, Australia’s head of state, who will appoint him prime minister if she is confident Rudd can control a majority in parliament.
“In 2007, the Australian people elected me to be their prime minister. This is a task I resume today with humility, with honour, and with an important sense of energy and purpose,” he told reporters, adding he wanted to rebuild trust with voters.
“In recent years, politics has failed the Australian people."
"There has just been too much negativity all round.”
Gillard, Australia’s first female prime minister, stuck to her promise to quit parliament if she lost the ballot.
“I am very proud of what this government has achieved which will endure for the long term,” a gracious but business-like Gillard told reporters, congratulating Rudd on his victory.
Senior ministers including treasurer and deputy prime minister Wayne Swan, education minister Peter Garrett, trade minister Craig Emerson and climate minister Greg Combet announced their ministerial resignations in the wake of the coup. Transport Minister Anthony Albanese was named Rudd’s deputy.