At the endorsement announcement, Fattah, 59, answered reporters' questions about his money woes.
Fattah said he would concentrate for now on fund-raising for the April 26 Democratic primary, "and then we'll worry about having a focus on raising money for my legal trust fund later."
"I can't do both," he said.
Trial for Fattah and four codefendants is scheduled to begin May 2, a week after the primary.
In their motion, Kevin Mincey, Thomas Fitzpatrick, and Shabrei Parker of Mincey & Fitzpatrick, and Riley Ross, who has his own practice, said Fattah had "failed to honor his fee agreement and has made no suitable arrangements to so comply."
They also wrote that they will face "an insurmountable financial burden" if they are "required to continue representation despite nonpayment."
Their filing did not specify how much Fattah's account was in arrears.
Mincey, Fitzpatrick, Parker, and Ross declined to comment on their motion or other details of their dealings with the embattled congressman.
Bartle scheduled a hearing for 10 a.m. Tuesday on the lawyers' request and ordered Fattah to attend.
Last Friday, the lawyers filed 10 motions seeking to dismiss parts of the indictment against Fattah and requesting that they be given some of the government's evidence.
Fattah praised the four lawyers' work, but said that their practices were too small to wait for payment and that he could not "keep up with the pace" after spending more than $300,000 on legal fees overall, including more than $100,000 on the four lawyers.
"I think they have probably irrevocably crippled the case against me in the pretrial motions that have been filed," Fattah said. "They've basically almost won this case already."
He said he would "probably wind up with a much larger firm" that can afford to be more flexible about when payments are due.
The four lawyers' motion addressed the money issue.
Fattah had "agreed to timely pay attorney's fees," they wrote. The congressman, however, "provided several preferred payment arrangements, and has knowingly defaulted upon each."
Fattah has been repeatedly advised of their intent to withdraw if they weren't paid, the lawyers wrote.
The congressman has had money problems since he was indicted in July.
On Sept. 30, Fattah's legal defense fund reported a balance of $9,000 in its filing with the IRS. The filing also showed that Fattah spent $100,000 on lawyers in its first month of operations, while raising $19,000 from his allies. He kept the fund afloat by lending it $85,000 from his own pocket and giving it $5,000 from his own PAC.
Fattah, who represents parts of Philadelphia and Montgomery County, is accused of accepting bribes and misusing campaign funds, charitable donations, and federal grant money he controlled to pay off personal debts. He has denied the charges and has said that they would not derail him from seeking a 12th term.
Fattah is being challenged in the primary by State Rep. Brian Sims; Lower Merion Township Commissioner Brian Gordon; Dan Muroff, leader of the Ninth Ward; and State Rep. Dwight Evans, whose campaign released a poll this week that showed him leading Fattah.
Williams told the crowd of about 70 that the event, held in the Center City headquarters of District 1199c of the National Union of Hospital and Health Care Employees, was not about "a poll that was paid for."
Most of them stressed the word delivered, saying Fattah has a record of helping his district, his city, students who want a college education, people who want to save their homes from foreclosure, and politicians facing tough times in an election.
"It's billions of dollars he brought back. and it would be billions of dollars that we would be losing," Brady said of the federal dollars Fattah has secured for the city. "Why would we lose that? Because somebody thinks that something went wrong? That don't work. It doesn't work in the United States. You're innocent until proven otherwise."
Fattah predicted that he will win a 12th term and that voters will not be "fooled by any of this nonsense."
"Don't worry about any of this other stuff," he said.
Assistant U.S. Attorney Paul Gray said he had no comment on the latest turn in the case.
The congressman's son, Chaka "Chip" Fattah Jr., 33, faces his own troubles before the same federal judge.
In November, he was convicted on bank- and tax-fraud charges in an unrelated case. He is scheduled to be sentenced in Bartle's courtroom on Feb. 2.