A former longtime aide to embattled Rep. George Santos, R-N.Y., pled guilty to a federal conspiracy charge Thursday and faces up to four years in prison for submitting false campaign finance reports.

While accepting the plea deal at a Long Island federal courthouse, Nancy Marks, who served as campaign treasurer for Santos' congressional bids in 2020 and 2022, said she and Santos falsely reported that he had loaned his campaign $500,000, despite not having the money to do so, and that the fake loan was to give the impression his campaign was well-funded in order to attract more donors.

Marks also admitted to giving the Federal Elections Commission a list of fake donors who had not actually given to the campaign, doing so without their permission.

EMBATTLED GOP REP. GEORGE SANTOS, EX-CAMPAIGN AIDE SEEM TO BE DISCUSSING PLEA DEALS WITH FEDERAL PROSECUTORS

Former George Santos aide Nancy Marks

Nancy Marks leaves federal court, Thursday, Oct. 5, 2023, in Central Islip, N.Y. Marks, the ex-campaign treasurer for U.S. Rep. George Santos pleaded guilty Thursday to conspiring to defraud the U.S. government and implicated the indicted New York Republican in court with submitting bogus campaign finance reports. (AP Photo/Mary Altaffer)

According to the Associated Press, the court's discussion surrounding the plea agreement, which comes with a recommendation Marks serve between 3 1/2 years to 4 years in prison, did not include a requirement for her to cooperate in the case against Santos.

The congressman was indicted in May on federal charges that he embezzled money from his campaign, lied in financial disclosures submitted to Congress and received unemployment funds when he wasn’t eligible.

Following her acceptance of the plea deal, Marks' attorney told reporters outside the courthouse that Santos "mentally seduced" her.

WATCH: TRUMP LAYS INTO ‘CORRUPT’ NEW YORK AG LETITIA JAMES FOR BEING ‘STUCK’ OFF CAMPAIGN TRAIL AT FRAUD TRIAL

Republican New York Rep. George Santos

Rep. George Santos, R-N.Y., poses for a photo outside the U.S. Capitol after the House failed to pass the Spending Reduction and Border Security Act on Friday, September 29, 2023. (Tom Williams/CQ-Roll Call, Inc via Getty Images)

"There’s a manipulation involved that had to do with her family and the death of her husband," the attorney said. "There were lies told." He later indicated Marks would be willing to testify against Santos if asked to do so.

Marks resigned from her position as Santos' treasurer in January after revelations he had lied about his life story and experience. The congressman later became treasurer of his own campaign.

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The Associated Press contributed to this report.