Australian Broadcasting Corp. reported that the latest Nielsen poll on Aug. 23 showed the opposition Coalition group headed by the Liberal National Party with a 6-point lead -- 53 percent to 47 percent. The Nielsen poll of 2,500 respondents has a margin of error of 2.6 percent.
If results were replicated evenly across the country on election day Sept 7, Labor would lose 10 seats, ABC reported.
Rudd, 55, remained upbeat after hearing the results of the latest Nielsen poll.
"I am old enough to remember what happened in a campaign 20 years ago, in 1993, where the then-Australian Labor PM Mr Keating entered the race as the underdog ... I believe we are heading in a similar direction here in this campaign," he said.
But Labor has been slipping steadily in Nielson polls which had Labor and the Coalition neck and neck at 50 percent on July 15.
Three weeks later, on Aug. 8, Labor fell back by four points -- 48 percent to the Coalition's 52 per cent.
Rudd's optimism that his underdog party will rise to the Coalition's challenge for power may be misplaced.
The Age newspaper reported that Rudd faces an uphill fight to retain his riding of Griffith in the city of Brisbane.
If he lost, he would be the third prime minister in Australian history to lose his own seat.
The last prime minister to do so was John Howard in 2007. The first was Stanley Bruce in 1929.
The Age reported that an opinion poll last week showed Rudd trailing -- albeit narrowly -- Bill Glasson, his Liberal National Party opponent in Griffith.
A Newspoll published by The Australian newspaper on Saturday had Glasson leading Rudd by 52 percent to 48 percent. The poll was based on 500 qualified voters in Griffith, in Brisbane's south.
Rudd, on the campaign trail in Brisbane, reiterated he was in confident his party's fortunes would turn around as long as it kept fighting hard.
"I'm in the business of fighting an election and fighting as hard as I can," he said before he cut short his electioneering to return to the capital Canberra for briefings on the Syrian crisis regarding suspected use of chemical weapons.
Liberal leader Tony Abbott, 55, said there were still two weeks before polling day and he expected Labor to embark on "the mother of all negative campaigns."
"As for the polls, frankly I don't believe them," Abbott said. "I think this is a very, very close race."
Rudd entered the election race after several months of Labor Party infighting that saw him win a leadership contest against Prime Minister Julia Gillard in late June.
Rudd, a former prime minister, challenged Gillard who, in 2010, similarly challenged Rudd and won, making her Australia's first woman prime minister.
Soon after Gillard lost to Rudd, she announced she would retire from politics and not run in the next election.