(CNN) - Washington Mayor Vincent Gray said on Tuesday he would not resign as prosecutors for the first time sought to tie him to a political scandal.
In an interview with CNN, Gray again denied any wrongdoing following the biggest guilty plea so far in the federal probe of a nearly $700,000 unlawful "shadow campaign" that was part of his successful 2010 mayoral run.
In court on Monday, prosecutors claimed that Gray was aware of the illegal fundraising and helped cover it up.
While the U.S. Attorney's office openly accused Gray of wrongdoing, it has not filed any charges at this point.
Gray denies any tie to the scheme that prosecutors said was masterminded by businessman Jeffrey Thompson, who pleaded guilty to conspiracy on Monday.
"I've made the clear for months now years, that I knew nothing about this and I had nothing to do with it," Gray told CNN on Tuesday.
He said he doesn't feel that he did anything wrong in the 2010 campaign, has operated "openly and honestly," and has no plans to step down.
"I have no intention of resigning. I haven't done anything and there is no reason to do that," Gray said in his downtown office.
"Remember, I am in the last year of my term, first of all, and I am not just going to walk away like that. I don't have a reason to walk away," he said.
Gray is running for reelection.
Four other top campaign aides have pleaded guilty to felonies related to the shadow campaign.
Thompson, 58, used his companies to funnel millions of dollars in off-the-book contributions to various federal and city candidates, court papers said.
Regarding Gray, Thompson and his unnamed co-conspirators allegedly disbursed "approximately $668,800 in excessive and unreported corporate contributions to pay for campaign services and campaign materials in coordination with and in support of" Gray's campaign, the court papers said.
According to prosecutors, Thompson used the code name "Uncle Earl" when dealing with Gray.
Gray said he and Thompson did employ the code name, but only because Thompson's business relied on government contacts and he feared retribution from Mayor Adrian Fenty, the incumbent who Gray defeated in Democratic primary balloting.
Gray said he didn't think this arrangement was odd because he "knew the incumbent had a reputation for seeking retribution."
In the upcoming Democratic primary, the incumbent Gray is facing challenges from at least 10 candidates, including four Democratic council members.
Gray told CNN that it appeared he was being made to take the fall for something he didn't do. He called the process "infuriating," especially considering the way the upcoming election has amplified the knocks on his ethics.
"I think it has resonated during the campaign already," Gray said about attacks on ethics. "People have brought it up and my suggestion to them is if they have anything that is factual associated with this, go down to see the U.S. attorney and report it."
Gray said that he believed voters would trust his leadership and the way he steered the city for the past three years, adding that these allegations don't fit with his history of public service.
"I think if you look at my life," Gray concluded, "my life is one that I am very proud of and this situation is one that, at best, I can describe as an anomaly."