A onetime challenger to U.S. Rep. Bob Brady will admit concealing a $90,000 payment that Brady's campaign gave him to drop out of the 2012 race, his lawyer said Wednesday.

But it is still unclear whether the case has placed the powerful Democrat in legal peril.

Jimmie Moore, a Philadelphia Municipal Court senior judge who resigned this week, will plead guilty as soon as next week to a single count of making false statements in his campaign-finance filings, lawyer Jeffrey Miller said.

Miller said he did not know whether the case would have a legal impact on Brady. He noted that the charge includes no claim of a conspiracy, but is more more akin to filing a false tax return.

"I don't know what evidence there is on Brady," Miller said. "I don't know what their intentions are."

In a criminal charging document filed Wednesday, federal prosecutors wrote that Brady had "agreed and understood" that the 2012 payments from his campaign to Moore's campaign "would be disguised" as the purchase of a poll.

Brady's lawyer, James Eisenhower, said Wednesday that the congressman "categorically" denied the claim that Brady knew the payments to Moore would be hidden.

"He never agreed to do anything illegal," Eisenhower said. "He never agreed to deceive anyone or anything."

A spokeswoman for the U.S. Attorney's Office declined to comment.

The charge offered the latest turn in a probe entangling the 72-year-old representative, who became chairman of the city Democrats in 1986 and is now dean of a congressional delegation he joined in 1998.

In late July, prosecutors disclosed that Carolyn Cavaness, Moore's campaign manager in the short-lived 2012 race, pleaded guilty to an identical false-statements charge. They said she and Moore set up a shell company to accept the $90,000 payment from Brady's campaign — money he could use to retire campaign debts — in return for his pledge to drop out.

The money was routed through two political consultants who falsified invoices intended to justify the payments, court records say.

After word broke of Cavaness' plea, Brady's lawyer said the prosecutor had misconstrued an innocent political transaction between the congressman and Moore, then a Municipal Court judge.

Rather than a secret payoff, they said, the money was paid in part to buy valuable and highly detailed polling data from Moore. In a skirmish of legal filings, prosecutors dismissed this, saying that the survey in question was stale and had relatively little value.

The criminal information says that Moore "knowingly falsified, concealed and covered up" the $90,000 payment, hiding it from the Federal Election Commission.

None of the money ever showed up on Moore's campaign-finance filings and less than half of that sum actually went toward paying down his campaign debts, according to Cavaness' plea agreement. Most of the money was spent on personal items by Moore and Cavaness, who was his ex-fianceé, the government said.

As sketched out in the Cavaness filing, prosecutors said that former Democratic Philadelphia Mayor W. Wilson Goode set up a face-to-face meeting between Brady and Moore to hash out the withdrawal. Goode set up the meeting at Goode's office in Philadelphia, but did not participate in it, the former mayor has said.

According to Eisenhower, Moore told Brady at the beginning of the meeting with Goode that he had decided to withdraw from the Democratic primary election. Moore asked for help in paying off his campaign debt and in returning to the Municipal Court bench.

In an interview Wednesday, Eisenhower described those actions as "very pro forma things in politics."

"We feel this is another example of the Justice Department attempting to criminalize politics," Eisenhower said. "There's nothing wrong with helping a vanquished opponent retire his campaign debt. It is the right thing to do."

Asked if Brady could be the next to be charged, Eisenhower said: "I really can't comment on that, other than to say that he has not been advised that he is the target of this investigation and he has not been charged."

But Eisenhower also noted that Moore appears headed toward a guilty plea on a charge that amounts to lying to the government.

"It appears this is about to be a swearing contest between Bob Brady and Jimmie Moore," Eisenhower said. "I would stack Bob Brady's credibility up against Jimmie Moore's any day."

Staff writer Andrew Seidman contributed to this report.