House Ways and Means Committee Chairman David Camp warned the Internal Revenue Service Thursday that it “will not see one more dime in taxpayer funding” until the agency institutes significant reforms to address a growing series of scandals, from the targeting of conservative groups to the payment of tens of millions of dollars in bonuses despite significant budget cuts.

The newly appointed head of the agency, Daniel Werfel, appeared before the panel to discuss his agency's internal investigation and plans for reform.

But Werfel was attacked by Republicans on the panel for the seemingly slow pace of the IRS internal investigation into reports that agents gave extra scrutiny to conservative groups seeking tax exempt status, and for the lack of disciplinary action against the employees who participated in the targeting.

“Has anyone been fired yet as a procedural matter? No,” Werfel responded, when asked about the fate of IRS employees involved in the scandals, citing laws that govern the dismissal of federal employees.

At one point during the hearing, Rep. Pete Roskam, R-Ill., crumpled up a page of a report given to the panel by the IRS, which was mostly blackened out by redactions.

“We’re seeing bureaucratic double talk,” Roskam said. “We’re seeing a bunch of nonsense. How can we possibly pierce through this?”

Democrats, meanwhile, are demanding new testimony from the Treasury Inspector General who uncovered the targeting of conservative groups. Democrats believe Inspector General S. Russell George left out evidence that progressive groups were also targeted, at the direction of House Oversight and Government Reform Committee Chairman Darrell Issa, R-Calif.

“We need to be a committee of facts and not a witch hunt if we plan to get to the bottom of this investigation,” Rep. Joseph Crowley, D-N.Y., said. “I demand that this Republican culture of intimidation against progressive groups be stopped and they be as outraged as Democrats were outraged when groups we don’t agree with politically or ideologically were being attacked or intimidated by the IRS.”

Earlier this week, George sent a letter to the Ways and Means panel’s top Democrat, Rep. Sander Levin, D-Mich., assuring him that “we did not find evidence” that progressive groups were also were being targeted by the IRS in the same way as Tea Party groups and other conservative organizations.

Democrats are not satisfied, however, and want George to return for additional grilling because of evidence that some progressive groups were at least initially singled out by agents.

“I think he should come back and talk to us and have him asked questions because, in terms of the selecting-out process, clearly, it involved progressive groups as well as tea party groups,” Levin said.

Werfel told lawmakers that there is no proof that the targeting was prompted by political bias or personal motivation.

“We certainly have evidence of neglect of duty,” Werfel said. “What we don’t have is evidence of criminal intent.”

But the investigation into the matter is not over, Werfel said, and will be much further along by the end of the summer.

Republicans, meanwhile, want to know why so many of the top IRS officials involved in the targeting are still collecting paychecks, among them Lois Lerner, who led the IRS Tax Exempt division. Lerner appeared before Congress last month, delivered a statement in her own defense before invoking Fifth Amendment rights and refusing to answer lawmakers' questions.

“Ok, what is Ms. Lerner doing right now,” a frustrated Rep. Jim Renacci, R-Ohio, asked Werfel.

But Werfel cited privacy laws.

“I can’t answer that question in this setting,” he responded.