Australian Prime Minister Julia Gillard called a shock leadership ballot of her ruling Labor party Thursday, as internal unrest mounted in a party floundering ahead of a general election in September.

Gillard s decision came after senior cabinet minister Simon Crean openly called for a vote, with the premier lagging badly in opinion polls and facing rampant leadership speculation."I have determined that there will be a ballot for the leadership at 4.30pm (0530 GMT) today. In the meantime, take your best shot," she told parliament.Gillard added that the 102-member caucus of Labor parliamentarians would also vote on the deputy leadership. Two members including Foreign Minister Bob Carr are overseas and so are not eligible to take part.

A defiant Gillard said her government would "fight and fight and fight" until the election in September."We will prevail in that election because the choice will be so clear and the right path for a stronger, smarter, fairer future will be so clear as well," she said.Former prime minister Kevin Rudd, who was ruthlessly ousted by Gillard in mid-2010, was expected to step forward as her main challenger, but was yet to make his position clear.

He resigned as foreign minister and challenged Gillard for the leadership in February 2012, but lost 71-31 and has since repeatedly pledged his support for the prime minister., another former Labor leader and party elder, cranked up the pressure on Gillard earlier in the day, siding with Rudd and saying the "stalemate has to end" to prevent the party from imploding.

"Something needs to be done to break this deadlock, to resolve the issue once and for all," he told reporters in his second hastily-called press conference of the day in Canberra."I am asking her to call a spill (vote) of all leadership positions."Crean, who warned the leadership speculation was "killing" the party, said he would stand for the deputy leader role, currently held by Treasurer Wayne Swan.

In response, Gillard sacked him from his position as arts minister in her cabinet.Crean met with Gillard on Wednesday evening and again Thursday to inform her of his decision, and said if she won the ballot he would resign.Asked if she could win the election, Crean said: "The Labor party can win the election."While Rudd has repeatedly pledged not to make another attempt on the leadership his supporters have been campaigning behind the scenes and Crean said he must declare his intentions. "He has got no option but to run," Crean said.

"I don t want any more games, I m sick to death of it, it s about time he stood up and instead of having his camp leak things, actually have the courage of his conviction and his belief."Gillard has been dogged by the speculation for weeks, with rumours fuelled by a government decision to try and introduce media reforms which the industry has united to fiercely oppose.

Reports said the government was expected to withdraw its media reform bills from parliament on Thursday in what would be a crushing failure for Gillard.Some ministers have stressed their loyalty to her, but reports have said any leadership vote between the two would be tight.Gillard became prime minister in mid 2010 when she ousted Rudd, who at the time had lost the support of powerful factional leaders.

She called an election which she failed to win outright from the sceptical public, gaining power only after cobbling together a coalition with a Greens MP and several rural independents to form a majority in the lower house.