A series of recent surveys have suggested Palin's presence on the ticket is hurting McCain's chances in the November 4 election, at a time when Democratic rival Barack Obama has surged clear in most key polls.
The inquests into what has gone wrong with McCain's campaign appear to have already begun, according to reports, with Palin's camp blaming the Arizona senator's senior advisers for mismanaging her contribution.
The Politico.com website cited four Republicans close to Palin as saying she had grown frustrated by advice given to her by campaign handlers, whom her supporters blame for a series of public relations gaffes.
The report said Palin was now increasingly willing to disregard orders from advisors, suggesting the Republican running mate was in the initial stages of forging her own identity for a future tilt at the White House.
"She's lost confidence in most of the people on the plane," said a senior Republican quoted by Politico, adding that Palin had already begun to "go rogue" in some of her public pronouncements on the campaign trail.
The Alaska Governor's supporters accused McCain strategist Steve Schmidt and senior aide Nicolle Wallace of blaming Palin for the failure of the campaign.
"These people are going to try and shred her after the campaign to divert blame from themselves," a McCain insider was quote by Politico as saying.
When asked to comment on the Politico story by AFP, Wallace said in an email: "I have no comment other than what's in the story, if people wish to throw me under the bus, my personal belief is that the graceful thing to do is to lie there."
Later Saturday, Politico quoted McCain advisers reacting angrily to the report, branding Palin a "diva."
The McCain sources said Palin had repeatedly gone "off-message" recently, suggesting she appeared to be looking out for herself.
"She is a diva. She takes no advice from anyone," the McCain source said. "She does not have any relationships of trust with any of us, her family or anyone else."
A McCain source quoted by CNN added: "She is playing for her own future and sees herself as the next leader of the party. Remember: Divas trust only unto themselves, as they see themselves as the beginning and end of all wisdom."
Another senior McCain adviser told the network: "This is what happens with a campaign that's behind; it brings out the worst in people, finger-pointing and scapegoating."
News of tensions within the McCain camp comes after polls suggested Palin -- who electrified the party when named as running mate in August -- is now dragging down the Republican ticket.
A Wall Street Journal/NBC News poll released on Wednesday found that Americans are less and less convinced she is worthy to serve as the country's number-two leader.
It confirmed the findings of an ABC/Washington Post poll released earlier this month which found that six in 10 voters saw Palin, 44, as lacking the experience to be an effective president. "A third are now less likely to vote for McCain because of her," the Post added.
After being found guilty of abusing her power as governor in the so-called "troopergate" scandal over the firing of her ex-brother-in-law, Palin now faces a second probe over whether she violated ethics rules in the affair.
Palin was also back in the headlines this week after it emerged 150,000 dollars had been spent on clothes for Palin since late August, potentially undermining her appeal as a down-to-earth working "hockey mom."
