House Oversight Committee Chairman Darrell Issa and IRS chief John Koskinen sparred over the pace in which the IRS is shipping documents to the panel, one of several probing the matter.

“Does a nonpartisan or nonpolitical agency withhold documents requested during a congressional investigation? The IRS does and did,” the California Republican said, calling the pace of document production “dismal.” “You’ve been more concerned with managing the political fallout.”

Issa repeated a threat to hold Koskinen in contempt of Congress if the documents are not produced to the committee.

The IRS is still managing the consequences of last year’s inspector general report, which detailed added scrutiny some agency officials gave to tea party conservative groups seeking tax exemptions. Most of the applicants that were delayed have received a response from the IRS, and granted tax-exempt status.

Koskinen, appointed by President Barack Obama after one IRS commissioner was pushed out and an interim chief took over temporarily, said IRS employees have spent nearly 100,000 hours and $8 million dollars sending more than 1 million pages of documents to the committees. That includes all documents initially requested by the Ways and Means Committee, another panel probing the matter, he noted.

“We are working through the process. We never said we wouldn’t not provide those. We will provide, we are actually trying to, in an orderly way, conclude the investigation,” Koskinen said. “You may want this investigation to go on forever.”

Republicans on the committee said blatantly they didn’t trust the IRS and accused Koskinen of stonewalling congressional investigations - even going as far as accusing Koskinen of coordinating testimony with the Treasury.

“Our witness today won’t get us [former IRS official Lois Lerner’s] emails. The guy who can give us the emails won’t give us the emails. The same people who pressured Lois Lerner to fix the problem are the same people who picked John Koskinen to finish the job,” said Rep. Jim Jordan.

Lerner is the the former IRS official who first acknowledged last May the IRS was targeting conservative groups seeking nonprofit status just as an inspector general’s report faulted poor management for the extra scrutiny. She has twice invoked the Fifth Amendment to avoid testifying before the Oversight Committee but has answered questions before the Department of Justice, further infuriating Republicans.

“I hope the investigations can now be concluded in the very near future,” said Koskinen.

Outstanding, Issa said, were additional documents from Lerner and former IRS official Holly Paz and current chief counsel William Wilkins. The committee is also seeking any communications from the IRS to the Treasury and the White House from February 2010 to Aug. 2, 2013.

The bulk of the hearing was a debate between Koskinen and the panel’s Republicans on whether the IRS planned to send all emails relating to Lerner’s tenure at the agency.

Koskinen said the agency sent up a prioritization system to first provide the committee with relevant emails but would be happy to work to provide all requested documents, though he cautioned that could mean millions of pages.

“We are going to respond to the subpoena. I’m just going to tell you that to comply with this subpoena, we’re going to be at it for years, not months,” he said.

Jordan said it was not the responsibility of the IRS to decide what is relevant for the committee’s probe.

“What don’t you understand about everything. We don’t care what you think is irrelevant. We asked for every single [email]…we want them all. What if there is an email from the White House [to Lerner] that says ‘keep up the great work. We like what you’re doing.’”

Democrats said Republicans were trying to keep the controversy alive in time for election season, after failing to connect the scandal to the White House.

“This is all to feed the base. It is designed to get certain groups all riled up in time for a midterm election. There are some of us here that wish you well and will try to cooperate with you,” said. Rep. Gerry Connolly (D-Va.). “[But] be aware, unfortunately this committee has a history of cherry picking facts.”