WASHINGTON (CNN) -- Top Republicans are demanding an apology from House Speaker Nancy Pelosi or proof to back her claim that the CIA misled Congress about the use of harsh interrogation tactics.

Speaker of the House Nancy Pelosi says the CIA misled Congress about harsh interrogation tactics.

Pelosi last week said she was briefed by the CIA on such techniques only once, in September 2002, and said she was told techniques like waterboarding were not being used.

Pelosi, D-California, said she learned from an aide that waterboarding had been used after other lawmakers were briefed in 2003.

A recently released Justice Department memo says the CIA used waterboarding at least 83 times in August 2002 in the interrogation of Abu Zubaydah, a suspected al Qaeda leader imprisoned at U.S. facilities in Guantanamo Bay, Cuba.

Rep. Pete Hoekstra, the top Republican on the House Intelligence Committee, said Monday that if Pelosi's accusations are not true, she may need to step down.

"She made some outrageous accusations last week where she said that the CIA lied to her and lied systematically over a period of years. That is a very, very serious charge," Hoekstra said Monday on CNN's "American Morning."

"Either the CIA needs to be held accountable for their performance during this time or the speaker needs to be held accountable and be responsible for the actions and the statements that she made last week. One or the other is correct, one or the other is wrong," he said. Watch Hoekstra's criticism of Pelosi »

Hoekstra wants the notes from the CIA briefing in question to be declassified, as does Pelosi. The House speaker says the notes will show she wasn't told that techniques such as waterboarding were being used. Related: GOP wants Pelosi held accountable

While Pelosi declined offers to appear on the Sunday talk shows, her critics fired away.

House Minority Leader John Boehner demanded Pelosi provide evidence to support her accusations.

"Lying to the Congress of the United States is a crime," Boehner, R-Ohio, said on CNN's "State of the Union." "And if the speaker is accusing the CIA and other intelligence officials of lying or misleading the Congress, then she should come forward with evidence and turn that over to the Justice Department so they can be prosecuted. And if that's not the case, I think she ought to apologize to our intelligence professionals around the world."

Several Democratic sources told CNN that privately, some congressional Democrats are baffled by Pelosi's decision to escalate the controversy last week by going after the CIA. But publicly support is strong for the speaker.

"Perhaps it wasn't one of her best press conferences. But certainly everyone in this caucus stands behind her," said Connecticut Democrat John Larson, one of Pelosi's closest allies in the House, on Monday.

Another Connecticut Democrat, Chris Murphy, said lawmakers are so focused on pushing through major policy changes on health care and energy that "there's not a lot of tolerance for distractions."

Conservative Indiana Democrat Baron Hill argued that people zeroing in on the speaker are trying to shift away from the broader issue of who authorized the harsh interrogation methods.

"I think a lot of people have lost focus on the people who put those torture policies in place in the first place," Hill said. "Nancy [Pelosi] didn't do anything wrong, in terms of the legalities, that I'm aware of. I don't know what she was told. I'm not here to cast judgment on her at all."

Hill said he made a half a dozen visits in his Indiana district over the weekend and no one raised the issue of Pelosi with him.

Rep. Gene Green, D-Texas, also downplayed any impact the story is having on the focus of getting major legislation passed in the House. "Health care, and now climate change, is now overriding any personal or political issue," Green said.

Pelosi's office is proactively reaching out to Democrats to inform them about the speaker's record on the issue. CNN obtained a copy of "talking points" that Pelosi's office distributed last week. The document lists the timeline and includes the point that the speaker repeatedly made at her press conference last week: "The only mention of waterboarding at that briefing was that it was not being employed."

Following Pelosi's remarks, CIA Director Leon Panetta on Friday stood up for the agency and challenged Pelosi's assertions.

"There is a long tradition in Washington of making political hay out of our business. It predates my service with this great institution, and it will be around long after I'm gone. But the political debates about interrogation reached a new decibel level yesterday when the CIA was accused of misleading Congress," Panetta said in a letter to employees.

"Let me be clear: It is not our policy or practice to mislead Congress. That is against our laws and our values," he said.

Panetta said the agency's records from September 2002 indicate that CIA officers "briefed truthfully on the interrogation of Abu Zubaydah, describing 'the enhanced techniques that had been employed.'"

Pelosi issued a response to Panetta and shifted her criticism from the CIA to the Bush administration.

"My criticism of the manner in which the Bush administration did not appropriately inform Congress is separate from my respect for those in the intelligence community who work to keep our country safe," she wrote.

CNN's Kristi Keck Dana Bash and Deirdre Walsh contributed to this report.

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