John McCain's campaign is lashing out at a new report in The New York Times alluding to the Republican presidential candidate’s relationship with a female lobbyist.

The article, published in Thursday's edition of the Times but released the day before on its Web site, revisits rumors spread during McCain's 2000 presidential campaign and tries to wipe the sheen off the Arizona senator's record as an anti-special interest crusader, McCain campaign communications director Jill Hazelbaker said

"It is a shame that the New York Times has lowered its standards to engage in a hit and run smear campaign," said Jill Hazelbaker, the McCain campaign's communications director. "John McCain has a 24-year record of serving our country with honor and integrity. He has never violated the public trust, never done favors for special interests or lobbyists and he will not allow a smear campaign to distract from the issues at stake in this election."

McCain will hold a press conference to address the report at 9 a.m. ET. Watch LIVE on FOX News Channel or FOXNews.com.

The Times article notes that McCain wrote to government regulators on behalf of a client of the lobbyist, Vicki Iseman, while he was chairman of the Senate Commerce Committee. It also discusses how campaign aides kept the two apart during the 2000 election for fear they were giving the impression they were having an affair.

McCain, 71, and Iseman, 40, long ago denied ever having a romantic relationship, but the story argues that "his confidence in his own integrity has sometimes seemed to blind him to potentially embarrassing conflicts of interest."

Rick Davis, McCain's campaign manager in 2000, told FOX News on Thursday that the campaign never had deep concerns about the relationship with Iseman or allegations of illicit favors for her client.

"I never had a single instance where this was a major issue in our campaign or any kind of an issue. And the idea that a decade later they have somehow uncovered some kind of a mystery is ridiculous," Davis said.

Hazelbaker likened the report to a "kind of gutter politics."

"There is nothing in this story to suggest that John McCain has ever violated the principles that have guided his career," she said.

McCain refused to comment Wednesday night about the article, saying he hadn't read it yet, but McCain campaign officials told FOX News that the story is "filled with falsehoods, inaccuracies and utterly unsubstantiated blind quotes."

Davis said the newspaper "didn't say that there was anything improper here. They just tried to imply it. They didn't say he had done anything for this lobbyist or this lobbying firm but they tried to imply it. If they are going to go this kind of route, why don't they tell us where they got the information?"  

Rumors of the newspaper's investigation first surfaced two months ago, and at the time, senior officials in the McCain campaign adamantly denied to FOX News any personal or professional wrongdoing. Officials also confirmed that McCain had hired Washington attorney Bob Bennett to prepare the campaign for the coming "smear." Bennett continues to be on retainer at this time.

When details of the newspaper's investigation emerged in December, McCain said he was going to battle the rumors much more vigorously than he fought other claims made against him in 2000.

"We’re getting close to the primary," McCain said in December before he emerged as the presumptive Republican presidential nominee. "These allegations are coming out at a very interesting time, and I have never, ever done a favor for any lobbyist or special interest group."

McCain's denials in December, including of the alleged affair, was in response to expectations that the Drudge Report was going to preempt the investigation before the newspaper actually reported it, campaign officials said.

Though Drudge did not print the story, campaign officials contend that the newspaper decided to go ahead and publish it now because The New Republic was planning a scathing critique of the newspaper for revealing the contents of its investigation.

McCain campaign officials said two weeks ago, they got a call from The New Republic asking for comment and information because it was planning a story on the newspaper's investigation.

Officials argued The New York Times, buffeted by reporter scandals in recent years, is covering itself, publishing a deliberate smear under pressure from the magazine and because of sensitivity to its reputation caused by reporter Judith Miller, who investigated Iraq's weapons of mass destruction program and was a key player in the subsequent CIA leak investigation involving Valerie Plame.

Click here to read The New York Times profile of John McCain.

Read the Washington Post report.

FOX News' Carl Cameron contributed to this report.