CNN  — 

Federal prosecutors on Tuesday accused Rep. George Santos of stealing donors’ identities and running up thousands of dollars in fraudulent charges on their credit cards.

The 10 new charges against Santos also include allegations that the New York Republican embezzled cash from his company and conspired with his former campaign treasurer to falsify donation totals in order to hit fundraising targets set by national Republicans, among other offenses.

The new indictment is another blow to Republicans on Capitol Hill, who are already in disarray after a small group of their own members led the way in ousting Kevin McCarthy as speaker last week. Santos was part of a class of newly elected New York Republicans who helped the party win a narrow House majority in the 2022 midterms and whose fate will be key to holding that majority in 2024.

Pressed Tuesday on whether he would resign, Santos said: “No, I will not.”

This fresh round of charges against Santos, called a superseding indictment, brings the total number of counts against him to 23. This indictment is wider in scope and provides new and damaging details about Santos’ alleged efforts to personally profit through his campaign.

It comes days after Nancy Marks, who worked as his treasurer during the 2022 campaign, pleaded guilty to one count of conspiracy to defraud the United States by committing one or more federal offenses.

“I filed a first quarter 2022 report stating that $500,000 was loaned to the campaign by co-conspirator #1 and the money was not received at the time,” Marks said during her allocution – a defendant’s formal address to the court. “As campaign treasurer, I knew that the loan had not been made at the time.”

In Tuesday’s filing, prosecutors from the Eastern District of New York provide messages between Santos and Marks discussing their efforts to effectively deceive the GOP into providing Santos with additional support by ginning up their fundraising totals.

In May, Santos, 35, pleaded not guilty to 13 federal charges. Those initial charges included seven counts of wire fraud, three counts of money laundering, one count of theft of public funds and two counts of making materially false statements to the US House of Representatives.

When asked about the indictment on Tuesday when leaving a GOP conference meeting, Santos told CNN’s Manu Raju, “I did not have access to my phone. I have no clue what you guys are talking about.”

Following his arraignment earlier this year, the congressman said that he has been “compliant throughout this entire process,” blasting the indictment at the time as a “witch hunt,” and said he would “fight my battle.”

Elected last year to represent a district that includes parts of Long Island and Queens, Santos has been under investigation in multiple jurisdictions and by the House Ethics Committee. The congressman has admitted to making some misleading claims about his education and financial status but continues to deny the more serious allegations. He has not admitted any crimes.

He announced in April that he will seek reelection in 2024 to represent New York’s 3rd Congressional District, which will likely be competitive turf next year. President Joe Biden would have won the district by about 8 points in 2020 under redrawn lines.

Democratic former Rep. Tom Suozzi, who left Congress for an unsuccessful 2022 gubernatorial bid, announced earlier Tuesday that he’s running for his old seat.

“The madness in Washington, DC, and the absurdity of George Santos remaining in the United States Congress is obvious to everyone,” he said in statement on social media.

This story has been updated with additional details.

CNN’s Clare Foran and Sam Fossum contributed to this report.