CENTRAL ISLIP, N.Y. — Former congressman George Santos, who was expelled from Congress last year, is expected to plead guilty Monday to some of the federal charges against him, which include wire fraud, money laundering and aggravated identity theft.

He has been charged with defrauding donors to his 2022 campaign by taking their money for his personal use and spending thousands of dollars on their credit cards. He is also charged with wrongfully claiming unemployment benefits and lying on his congressional financial disclosure statements.

The ex-congressman, who is scheduled to appear in federal court Monday afternoon, will face a potential prison sentence. The charges of wire fraud carry a sentence of up to 20 years.

Santos, now 36, had just been elected to Congress in 2022 when news reports began exposing a slew of lies he had told about his background. He claimed to have studied at educational institutions he never attended for high school, college and business school. He said he worked at the Wall Street firms Goldman Sachs and Citigroup; he did not. He falsely said that his mother was inside the World Trade Center during the attacks of Sept. 11, 2001 and that his grandparents fled the Holocaust.

Months into his term, in May 2023, he was charged with 13 counts of defrauding donors and falsely claiming unemployment benefits. Prosecutors accused him of spending donors’ money on designer clothes for himself and telling the state of New York he was unemployed for almost a year starting in the summer of 2020, when he was in fact working for a Florida investment firm.

He allegedly collected more than $24,000 in public benefits to which he was not entitled.

The Florida investment firm, Harbor City Capital, was forced to shut down in 2021 by the Securities and Exchange Commission, which called the company “a classic Ponzi scheme.” Santos has said he was unaware of any wrongdoing at Harbor City.

In his brief time in Congress, Santos co-sponsored legislation cracking down on abuse of unemployment insurance — the same crime with which he was later charged.

In October, prosecutors expanded the indictment to include aggravated identity theft, allegedly that Santos used the personal information of his family members without their permission to make it appear to the Federal Election Commission that his campaign had more donors than it had. Prosecutors also alleged that Santos repeatedly charged his campaign donors’ credit cards without their permission.

Nancy Marks, who was treasurer of Santos’s campaign, pleaded guilty earlier to related charges.

Santos was expelled from Congress in December by a vote of 311-114. It was a rare action taken only five times in history: Three members were expelled in 1861 for supporting the Confederacy, and one each in 1980 and 2002 for bribery convictions.

This story will be updated.