THE first people's verdict on Monday's leadership showdown reveals Kevin Rudd is Labor's best chance of winning an election.

Three separate polls released overnight show that Mr Rudd is still popular with Australians, with voters preferring him as Labor leader over Julia Gillard by wide margins in all three polls.

He gets the nod by 58 per cent in a Nielsen Poll, 53 per cent in a Newspoll and 52 per cent in a Galaxy Poll, while Ms Gillard polled 34, 30 and 26 per cent respectively.

But while voters favour Mr Rudd, only half in the Nielsen survey said Labor should swap leaders, and the Coalition continues to lead Labor on a two-party preferred basis, although the margin is tighter with Mr Rudd at the helm.

The Galaxy Poll for the Herald Sun suggest Labor would lose about 14 seats under Ms Gillard and six seats under Mr Rudd.

And almost six out of 10 polled by Galaxy said the independents should force an early election if there is a change of PM.

Mr Rudd said he was contesting the leadership ballot to "finish the job the Australian people elected me to do" in 2007.

He revealed if he won the top job he would review the carbon tax after six months, holding open the prospect of cutting the $23-a-tonne tax.

Mr Rudd said Ms Gillard had "lost the trust" of voters and Labor was "heading for the rocks" of a crushing defeat at the election if it did not change leader.

But Ms Gillard said only she had the "courage and discipline" to make the tough decisions for the nation's future and, unlike Mr Rudd, she had the skills to "deliver the big reforms".

Mr Rudd's wife Therese and daughter Jessica launched their own media blitz to promote the people-power campaign pitched by the former PM. He urged citizens to tell their Labor MP how to vote in the ballot.

Labor number crunchers claim Ms Gillard is on course for a clear victory, with about two-thirds of the 103 votes. Her supporters say Mr Rudd might get less than 30 votes.

Mr Rudd's camp says he will get more than that, but concedes Ms Gillard is on track to win. They are hoping MPs will change their mind during the weekend.

Mr Rudd said he would only have one shot at Ms Gillard, and if he lost he would go to the backbench and "not challenge Julia a second time". But he has left open the option of being drafted for the leadership in the future.

Ms Gillard has also promised to renounce any further ambition if she loses.

Galaxy Research pollster David Briggs told the Herald Sun: "If Kevin Rudd was to lead the Labor Party, the poll suggests it would bring Labor back into contention."