CANBERRA (AP) - Speculation is intensifying that Prime Minister Julia Gillard will be challenged soon for her party's leadership as opinion polls increasingly suggest her government would be crushed at Australia's upcoming elections.

Centre-left Labour Party government lawmakers publically stood by their beleaguered leader on Wednesday. But The Australian Financial Review newspaper reported three unnamed senior Gillard backers as saying that support among government ranks for her predecessor Kevin Rudd was growing.

Part of Mr Rudd's appeal is opinion polling that shows he would be a far more popular choice as prime minister than Gillard.

Mr Rudd led Labour to victory at elections in 2007, then was deposed by his then-deputy Gillard in an internal party coup in 2010.

He challenged her last year but was roundly defeated in a ballot of Labour lawmakers by 71 votes to 31.

Members of her inner circle told the newspaper that Mr Rudd might now have the support of most of the party or could be as close as five votes away from a majority.

Nine Network television news reported on Tuesday that Rudd backers had raised with colleagues the prospect of a leadership challenge which could happen this week before Parliament is adjourned for seven weeks.

Mr Rudd has ruled out mounting a second challenge himself but has left open the possibility his colleagues could nominate him.

Ms Gillard told Parliament on Tuesday that she would lead her government to victory over the conservative opposition coalition led by Mr Tony Abbott at elections Sept. 14.

"It will be a contest counter-intuitive to those believing in gender stereotypes, but a contest between a strong feisty woman and a policy-weak man, and I'll win it," she said.

A party leadership change could trigger earlier elections. Ms Gillard rules a minority government with the support of two independent lawmakers and a legislator from the Greens party.

But one of those independents, Mr Tony Windsor, warned on Wednesday that he would not necessarily support a government led by Rudd.

"Essentially the deal would be off if there's a leadership change," Mr Windsor said. "I haven't signed up to be a camp follower of the Labour Party and all its machinations."

Asked at a news conference if Ms Gilllard still enjoyed the support of her government colleagues, Attorney-General Mark Dreyfus replied: "Absolutely."