The chairman of the Democratic City Committee on Monday called on State Rep. Leslie Acosta to resign, three days after it was revealed that she secretly pleaded guilty to federal felony charges this year without informing party leaders that she had been charged.

U.S. Rep. Robert Brady (D., Pa.) said Acosta - a North Philadelphia Democrat running unopposed for a second term - called him to apologize after the Inquirer reported Friday on her plea in March to one count of conspiracy to commit money laundering, details of which remain under seal.

Describing their conversation, Brady said he urged her to step aside before Election Day and was told she planned to make a decision about her political future by the end of the week.

"She should resign now," Brady said Monday. "There's no reason for her to stay."

Acosta, 45, has not spoken publicly about her plea since the report. When the state House reconvened Monday, she was nowhere to be found.

Her Capitol office remained dark. A woman who answered the phone at her district office in North Philadelphia said she was not sure where Acosta was.

And although a Democratic caucus spokesman said early Monday that Acosta had informed party leadership that she planned to attend the first day of the House's fall session, he later said that her plans had changed and that she would not be returning to the Capitol this week.

Despite her absence, Acosta was recorded as voting on House resolutions three times Monday during a 30-minute span, a by-product of a publicly criticized practice in the Capitol called ghost-voting, in which colleagues cast votes on behalf of missing members.

The case against her involves an alleged embezzlement scheme at a Fairhill mental health clinic at which she worked years prior to taking office.

Her admission of guilt six months ago all but assures she will become ineligible to hold on to her seat once she is sentenced at a hearing set for early next year - nine days after she would be scheduled to be sworn in for a second term.

Acosta announced her reelection bid in January - two months after sealed charges were filed against her by way of a criminal information, a charging document typically used when a defendant has agreed to plead guilty.

"She just kept it all completely quiet," said Brady, expressing frustration over her decision. "It would have been so much easier had she said something the day it happened and within the time frame to replace her with another candidate."

Over the weekend, Acosta contacted support staff for the House Democratic caucus for the first time to discuss her legal situation, but had not yet been in contact with Minority Leader Frank Dermody (D., Allegheny), his spokesman, Bill Patton, said Monday.

Should Acosta return to Harrisburg, she may face a frosty reception.

A source familiar with internal legislative discussions about how to handle her situation called it "very likely" that should she decide to remain in office, the House would vote to refuse to seat her when the new, two-year legislative session begins early next year.

The last time such a legislative rebuke was even considered was in 1995, when State Rep. Thomas Stish of Luzerne County switched parties a week after being reelected and handed control of the House to Republicans.

For now, said Patton, Acosta "continues to serve as a member of the House until her sentencing. Nothing has changed in that regard."

Sources familiar with Acosta's case say she is cooperating in the prosecution of Renee Tartaglione, her former boss at the Juniata Community Mental Health Clinic and part of a Northeast Philadelphia political dynasty.

Tartaglione, facing trial in November, is accused of embezzling hundreds of thousands of dollars from the publicly funded clinic she founded with her husband in 2002 to serve low-income patients.

Prosecutors have not accused Acosta of personally benefiting from the theft. But she admitted to knowingly aiding Tartaglione by accepting checks from the clinic worth thousands of dollars between 2008 and 2012 for work she did not perform, cashing them and kicking the money back to her former boss.

Tartaglione has denied any wrongdoing.

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