Kevin Rudd will once again be prime minister after emerging victorious from the Australia Labour (Labour) Party leadership ballot.

He defeated Prime Minister Julia Gillard, who has pledged to retire from politics at the upcoming election, by 57 votes to 45 on Wednesday night, in Canberra.

The Mandarin-speaking Rudd becomes Labour leader and will now look to be sworn in as prime minister by the governor-general, Thursday morning.

The new deputy prime minister is Anthony Albanese who replaces Wayne Swan.

Gillard rolled out Rudd three years ago as prime minister to become the country's first woman prime minister.

Meanwhile, Malaysian-born Penny Wong was elected unopposed as leader in the Senate which makes her the third most powerful politician in Australia after the prime minister and his deputy.

Wong, one of the most respected and admired politicians in Australia, was born in Kota Kinabalu, Sabah, and was a lawyer in Adelaide before entering parliament.