Rep. Elijah Cummings, D-Md., accused House Oversight and Government Reform Committee Chairman Darrell Issa, R-Calif., of "scuttling" an opportunity to have former IRS official Lois Lerner testify about the targeting of conservative groups, a charge Issa's team attributes to dishonest statements from Lerner's attorney.

Cummings told Issa that Lerner would have testified if the hearing had been delayed one week, from March 5 to March 12, so she would have more time to prepare. But her attorney pulled her out of the hearing when Issa told "Fox News Sunday" that she would testify on March 5.

"Ms. Lerner's attorney explained that he was stunned that you refused to take 'yes' for an answer when he offered to have Ms. Lerner testify with a one-week extension," Cummings wrote to Issa in a Thursday letter. "You refused to consult with other committee members about this offer, which all Democratic members would have accepted instantly. Instead, you went on national television and made inaccurate statements that ended up scuttling the offer and causing Ms. Lerner's attorney to lose faith in the credibility of our committee."

Cummings cites a Politico report that explained Issa's statement that the hearing would take place on March 5 as a mistake made because "panel staff . . . didn't realize at the time that [Lerner attorney William Taylor's] offer was contingent on the delay."

A spokesman for Issa countered that Cummings doesn't know the facts. "Ranking Member Cummings is ignorantly opining on conversations in which neither he nor his staff participated," Frederick Hill told the Washington Examiner in an email. "Lois Lerner’s lawyer, his apparent source, has made numerous false and evolving claims about her willingness to testify and why she rescinded an offer after seeing new information gathered by the Oversight Committee about her involvement in targeting."

Hill points to the fact that Taylor contradicted Issa without telling reporters about the ongoing negotiations, after Issa said that he had promised Lerner would testify. “I do not know why Issa said what he said,” Taylor told Politico, without acknowledging that he was talking to Issa's team about having Lerner make an appearance if they agreed to delay the hearing by one week.

Hill said Issa's statement that the hearing would take place on March 5 only reflected the status quo schedule as negotiations with Lerner's attorney took place. Hill suggested that Taylor pulled Lerner out of the hearing after getting a sense, from Issa's Fox News interview, of the evidence that the committee had against his client.

"Events indicate that the offer that they made, that they rescinded, that [was] because she didn't want to testify," he told the Examiner, noting that Lerner is unwilling to talk to any committee, not just Issa's.

The broadside came as Cummings replied to Issa's letter asking if he was negotiating an immunity agreement with Taylor.

"[Y]ou can rest assured that neither I nor my staff have been in discussions with Ms. Lerner's attorney about immunity, and I have no intention of seeking immunity on her behalf," he wrote.

The House committee voted to hold Lerner in contempt on Thursday, a day after the Ways and Means Committee recommended she be prosecuted.