Former U.S. congressman George Santos pleaded guilty on Monday to wire fraud and aggravated identity theft, short-circuiting the federal fraud case that led to his expulsion from Congress just weeks before it was set to go to trial.

"I betrayed the trust of my constituents and supporters. I deeply regret my conduct," the New York Republican said as he entered the plea in a Long Island, N.Y., courtroom.

Santos, 36, said he accepted responsibility and intends to make amends. He faces more than six years in prison under federal sentencing guidelines and owes at least $370,000 US in restitution.

U.S. District Judge Joanna Seybert scheduled Santos's sentencing for Feb. 7, 2025.

Santos was indicted on felony charges that he stole from political donors, used campaign contributions to pay for personal expenses, lied to Congress about his wealth and collected unemployment benefits while actually working.

WATCH | George Santos expelled from U.S. Congress: 

George Santos expelled from U.S. Congress

George Santos has been expelled from the United States House of Representatives after a series of criminal charges and ethics investigations. He is only the sixth person ever to be ousted from the chamber.

He was expelled from the U.S. House of Representatives after an ethics investigation found "overwhelming evidence" that he had broken the law and exploited his public position for his own profit.

The case had been set to go to trial in early September. If that had happened, federal prosecutors said Monday that they were prepared to call some 40 witnesses, including members of Santos's campaign, employers and family members.

Once touted as a rising star

Santos was once touted as a rising political star after he flipped the suburban district that covers the affluent North Shore of Long Island and a slice of the New York City borough of Queens in 2022.

But his life story began unravelling before he was even sworn into office. At the time, reports emerged that he had lied about having a career at top Wall Street firms and a college degree, along with other questions of his biography.

New questions then emerged about his campaign funds.

He was first indicted on federal charges in May 2023, but he refused to resign from office.

WATCH | Santos expresses continued support for Trump: 

'Always have, always will': George Santos on his support for Trump

CBC’s senior Washington reporter Katie Simpson spoke with disgraced former congressman George Santos during a live televised interview in New Hampshire Tuesday night. He was at a watch party to support Donald Trump at the Republican primary.

Santos has previously maintained his innocence, though he said in an interview in December that a plea deal with prosecutors was "not off the table."

Asked if he was afraid of going to prison, he told CBS 2 at the time: "I think everybody should be afraid of going to jail, it's not a pretty place and, uh, I definitely want to work very hard to avoid that as best as possible."

Separately on Monday in Manhattan, District Court Judge Denise Cote tossed out a lawsuit in which Santos claimed that late-night host Jimmy Kimmel, ABC and Disney committed copyright infringement and unjustly enriched themselves at his expense by using videos he made on the Cameo app for a Jimmy Kimmel Live segment. The judge said it was clear that Kimmel used the clips, which were also posted to YouTube, for the purposes of criticism and commentary, which is fair use.

Santos had begun selling personalized videos on Cameo in December shortly after his ouster from Congress. He subsequently launched, then quickly abandoned, a longshot bid to return to Congress as an independent earlier this year.

In a radio interview that aired Sunday, Santos said he has taken comfort in being a "somewhat private civilian" again.

"I really don't miss the rubber chicken dinners and the rah-rah-rah parties and fundraisers," he said of his former life.

With his criminal trial looming, he said in the WABC interview that he was "terrified."

"This is not absolutely an easy process to go through. It really hurts and it really messes with your psychological health," he told host Cindy Adams.

As the trial date neared in recent weeks, Santos had sought to have a partially anonymous jury, with his lawyers arguing in court papers that "the mere risk of public ridicule could influence the individual jurors ability to decide Santos's case solely on the facts and law as presented in court."

He also wanted potential jurors to fill out a written questionnaire gauging their opinions of him. His lawyers argued the survey was needed because "for all intents and purposes, Santos has already been found guilty in the court of public opinion."

Judge Seybert agreed to keep jurors' identities public but said no to the questionnaire.

Prosecutors, meanwhile, had been seeking to admit as evidence some of the financial falsehoods Santos told during his campaign, including that he'd worked at Citigroup and Goldman Sachs and that he had operated a family-run firm with approximately $80 million US in assets.

Two Santos campaign aides previously pleaded guilty to crimes related to the former congressman's campaign.

His ex-treasurer, Nancy Marks, pleaded guilty last October to a fraud conspiracy charge, implicating Santos in an alleged scheme to embellish his campaign finance reports with a fake loan and fake donors. A lawyer for Marks said at the time his client would be willing to testify against Santos if asked.

Sam Miele, a former fundraiser for Santos, pleaded guilty a month later to a federal wire fraud charge, admitting he impersonated a high-ranking congressional aide while raising money for Santos's campaign.