WASHINGTON — For weeks, Republicans have said their objections to the Consumer Financial Protection Bureau are substantive, and not based on worries about the agency's de facto leader, Elizabeth Warren.

But at a House hearing Tuesday, GOP members launched a series of personal attacks on Warren, suggesting she was lying and sometimes interrupting her responses. The atmosphere reflected just how polarizing a figure Warren has become, with Republicans seeing her as a symbol of an overreaching government and Democrats viewing her as a defender of the American consumer.

Strangely, the most heated exchange had nothing to do with the agency and its role in regulating banks, but focused on what time Warren would be allowed to leave the hearing. Warren said she had struck an agreement to leave after an hour of testimony with Rep. Patrick McHenry, chairman of the House Oversight's subcommittee on financial institutions — only to have the North Carolina Republican adamantly deny it.

"You had no agreement," McHenry said. "You're making this up, Ms. Warren."

The comment angered Rep. Elijah Cummings, the subcommittee's top Democrat, who said McHenry had committed a breach of protocol.

"Oh, Mr. Chairman," Cummings said. "I'm trying to be cordial here, but you just accused the witness of lying. I think you need to clear this up with your staff."

McHenry later issued a press release that said the incident was emblematic of the runaway nature of Warren and her agency.

"I was shocked by Ms. Warren's blatant sense of entitlement," McHenry said. "She was apparently under the assumption that she could dictate a one-hour time limit for her testimony to Congress and that we were there at her behest instead of the other way around. This is just further example of her disregard for congressional oversight."

It was the second time during the hearing that McHenry suggested Warren was not telling the truth. Earlier in the hearing, McHenry pressed Warren on her role in helping multiple government agencies in a pending settlement with the top five mortgage servicers. The North Carolina lawmaker argued that Warren had misled Congress when she testified on March 16 that she was just providing advice to Treasury Secretary Tim Geithner on the issue. McHenry pointed to a document prepared by the CFPB that was circulated to other state and federal officials that called for principal reductions as part of any settlement with the servicers.

"You said you were providing advice to the Treasury secretary in your sworn testimony," McHenry said. "And what is now apparent is you're providing advice to the attorney general of Iowa in their suits against mortgage servicers. Is that correct?"

Warren said she had tried to be clear she provided advice to any agency that sought it.

"The secretary of the Treasury asked for advice, and we gave advice," she said. "We also gave advice — at his instruction — we gave advice to other federal agencies and we gave advice where asked."

Democrats said McHenry had gone too far.

"Professor, it's obviously serious when someone accuses anyone of lying to Congress," said Rep. Mike Quigley, D-Ill., coming to Warren's defense.

Rep. John Yarmuth, D-Ky., apologized to Warren "for the rude and disrespectful comments from the chairman."

"That indicates to me that this hearing is all about impugning you, because people are afraid of you and your ability to communicate in very clear terms to consumers," Yarmuth said.

The hearing comes at an awkward time for Warren. For eight months she has served as the Obama administration's point person on setting up the CFPB, but she has not been nominated as its director. As recently as two weeks ago, several sources expected President Obama to finally nominate Warren and perhaps seek a recess appointment for her after Senate Republicans vowed to block any nominee unless structural changes were made to the agency.

But media outlets suggested Tuesday that top Massachusetts Democrats were also urging Warren to run for the Senate next year.

During the hearing, Warren declined to say whether or not she would accept a recess appointment to be the bureau's permanent director.

"It is up to the president of the United States under Dodd-Frank to make a nomination," she said. "It would not be appropriate, I think, for anyone to be speculating about that."

Republicans also grilled Warren on the salaries of prospective employees, the pay discrepancy with other federal agencies, the bureau's expected budget and whether consumer complaints will be made public.

Rep. Trey Gowdy, R-S.C., pressed Warren on how she will interpret certain statutory language.

"Ultimately," Warren said, "it will fall to this bureau through a lengthy process to interpret this [language] on a case-by-case basis. I believe it would be irresponsible for me to stand here and pop off about how I would interpret particular words."

When Warren tried to elaborate in answers to several of his questions, Gowdy insisted that she provide yes-or-no responses. "Mr. Chairman, I give up," he said when his time had expired.

For all the piling on from Republicans, Democrats tried to counter with words of encouragement.

"I don't care what happens in the hearing today," Cummings said. "I don't care what is said. I'm begging you to keep the fire. We need you. We really, desperately need your passion, your concern."

"Thank you for synchronizing your conscience with your conduct," he added.