In their first substantive attack on evidence that could feature in their client's corruption trial, U.S. Rep. Chaka Fattah's attorneys accused prosecutors of lobbing disingenuous accusations and innuendo at members of the congressman's family.

Lawyer Samuel W. Silver, in filings late Monday in U.S. District Court, said government lawyers had twisted the meaning behind recorded conversations they hope to use at trial. He specifically cited a tape that prosecutors flagged this month, saying it could expose Fattah's wife, former NBC10 news anchor Renee Chenault-Fattah, to possible criminal liability.

"The government's . . . accusations of wrongdoing against [Chenault-Fattah] are both gratuitous and offensive," Silver wrote. "They are also bitterly ironic, in light of the government's accusations . . . that it is Congressman Fattah who is attempting to poison the well through public statements."

The lawyer's reply comes amid an increasingly acrimonious fight over the conduct of all parties in the case.

Since his indictment last year, Fattah, a Philadelphia Democrat, has accused the government of waging a years-long witch hunt against him and members of his family.

Prosecutors have shot back, asking U.S. District Judge Harvey Bartle III to prevent Fattah from making those arguments - which do not directly respond to the allegations against him - at his trial on racketeering conspiracy charges next month.

Tensions flared again April 1 as the government sought Bartle's permission to present two separate recordings of the congressman's wife and his son that they say will help prove their case.

The first, prosecutors believe, shows that Chenault-Fattah was at least aware of - if not a direct participant in - a sham car sale they allege the congressman set up to hide an $18,000 bribe they say he received from lobbyist Herbert Vederman.

Fattah is accused of accepting the money in exchange for offering Vederman's girlfriend a job that "required little to no work" on his congressional staff. According to the indictment, the two covered up the bribe by having Vederman pretend to buy Chenault-Fattah's 1989 Porsche convertible.

While the title was transferred in January 2012, Chenault-Fattah kept the car for years afterward. She has since said she agreed to store the Porsche in her garage after Vederman bought it because he did not have a place to park it at the time.

Later, when the vehicle became part of the criminal investigation into her husband's activities, Fattah family lawyers advised her to keep it, she has said.

The recording prosecutors hope to introduce at trial next month is of a November 2012 conversation Chenault-Fattah had with her insurer as she tried to change the policy on the Porsche for the winter. They contend the conversation shows Chenault-Fattah still considered the car to be hers more than 10 months after its purported sale, proving the transaction was a fake.

In his filing Monday, Silver, the lawyer for the congressman, balked at the government's logic.

"A statement supposedly expressing an intent to keep the car in a garage over the winter is a far cry from a statement that the speaker owns the car," he wrote. "In fact, the statements are perfectly consistent with her having sold the Porsche months earlier and, for a multitude of reasons, the new owner simply leaving it with [Chenault-Fattah] to store in her garage, including in the winter when nobody would be using it."

The second recording - of Fattah's son, Chaka "Chip" Jr. - was already played before a separate jury last year, as the younger Fattah faced his own trial on bank and tax fraud charges.

Prosecutors hope to play it in the congressman's case, alleging that it bolsters their contention that Vederman funneled additional bribe money to Fattah through his son in 2010 to buy the congressman's support in the lobbyist's failed bid to receive a White House appointment as an ambassador.

A year later, FBI agents sent Fattah Jr.'s former business partner and roommate Matthew Amato to meet with him while wearing a wire. Over drinks at the R2L restaurant and lounge on the 37th floor of Two Liberty Place, Amato asked the younger Fattah if he was doing anything to help his father's political campaigning.

Fattah Jr. responded: "Nah, I mean if he calls me and needs a couple of stacks, I got him. . . . Well, he only makes 160."

Prosecutors contend that the "couple of stacks" Fattah Jr. mentioned refers to more than $5,000 in checks Vederman wrote him between April and October 2010. The younger Fattah, they say, passed along at least $2,310 of that money to his father.

But the congressman's lawyers maintain that the government's interpretation of the recording is a stretch, noting that the money exchanges between Vederman and Fattah Jr. occurred a year before Amato made his recordings.

"At most, the vague exchange indicates that Congressman Fattah's son gave his father money occasionally to help him out. Period. Full stop," they wrote.

What's more, they said, prosecutors offered an entirely different explanation for "the couple of stacks" statement to the jury that convicted Fattah Jr. last year.

In closing arguments in that case, Assistant U.S. Attorney Eric Gibson said Fattah Jr. was referring to $4,000 he gave his father in 2011 - part of a bank loan the younger man received through fraud.

"Perhaps the government believes that because the statement at issue is so vague and innocuous," Silver wrote, "it can mean one thing at one trial and another thing at another trial."

Prosecutors have declined to comment on pretrial filings. Bartle is expected to rule on the recordings and several other pretrial issues in the coming weeks.

In addition to the alleged bribery scheme with Vederman, Fattah is accused with three others of misusing campaign cash, charitable contributions, and federal grant money under his control to pay off debts and enrich members of his inner circle.

jroebuck@phillynews.com

215-854-2608 @jeremyrroebuck