Kevin Rudd has been sworn in as prime minister of Australia, a day after he ousted Julia Gillard as leader of the Labor Party.
She immediately stepped down as PM, saying she would leave politics.
The change comes ahead of a general election, which polls suggest Labor is set to lose.
Opposition leader Tony Abbott called on Mr Rudd to name an election date sooner than 14 September – the day which had been set by Ms Gillard.
“The Australian people are yearning to make a choice. The Australian people are well and truly over this low and dishonourable parliament,” he told a news conference.
This is the latest twist in a long and bitter rivalry between the two politicians – but it could be the last as Ms Gillard has said she will now leave politics.
Wednesday’s leadership test was the third faced by Ms Gillard since she ousted Mr Rudd as prime minister in 2010.
Despite their bitter rivalry, Mr Rudd praised his predecessor, describing her as a woman of extraordinary intelligence, with great strength and energy.
“Julia, as prime minister and prior to that as deputy prime minister, has achieved much under the difficult circumstances of a minority government,” he told a news conference after his victory.
Mr Rudd is more popular with voters than Ms Gillard, and many believe Labor will perform better in the election under him.
Source: BBC