But that criticism did not come from Newt Gingrich, who has emerged as a severe critic of Speaker Nancy Pelosi, talking about her and her dispute with the Central Intelligence Agency. It was Ms. Pelosi talking about Mr. Gingrich in 1997, when he was speaker and she was one of four House members who conducted a contentious ethics investigation that ended badly for him.

Now, the Pelosi-Gingrich relationship has become one of the more interesting subtexts of the furor over Ms. Pelosi’s assertion that she was misled by the intelligence agency in 2002, rekindling the tension between the two and underscoring how both political parties have at times waged war against the House speaker to advance their political goals.

The situation comes as Mr. Gingrich appears eager to fill a vacuum in the Republican leadership, asserting himself anew as he considers a possible White House bid in 2012.

Given those ambitions, Mr. Gingrich, who last year appeared in an advertisement on climate change in which he and Ms. Pelosi shared a love seat in front of the Capitol, is no longer feeling quite so warm toward the speaker. He has made feverish calls for her removal, and on Friday his Web site was dominated by a picture of Ms. Pelosi alongside the headline “Why Speaker Pelosi Should Step Down,” after she said C.I.A briefing officers told her only that tough interrogation procedures had been legally cleared, not that they had been used.

“When you become speaker of the House, you no longer have the luxury of being dishonest, demagogic and destructive,” Mr. Gingrich said in an interview.

Ms. Pelosi essentially accused Mr. Gingrich of all three more than 12 years ago as she urged her colleagues to endorse an ethics committee rebuke of him for using tax-exempt money to promote political goals and for providing false information to the special ethics panel Ms. Pelosi was on. She said Mr. Gingrich spoke often of ethics but did not make them a priority and had put the Congress in a bad light.

“Mr. Gingrich’s statements lead me to one conclusion: that Mr. Gingrich, in his dealings with the committee, is not to be believed,” said Ms. Pelosi, who urged Republicans to weigh whether Mr. Gingrich should remain the pre-eminent figure in the House. “He is technically eligible. I hope you will make a judgment as to whether he is ethically fit.”

Ms. Pelosi, who on Friday said she was finished talking about the C.I.A. imbroglio, was not about to be drawn into a discussion of Mr. Gingrich and whether he was seeking revenge for her role in the ethics case.

“I don’t think about it,” she said.

Mr. Gingrich dismissed any suggestion that personal payback was involved, saying he was acting out of a deep concern for national security, which he said Ms. Pelosi had seriously harmed by undermining morale at the intelligence services.

“She wasn’t particularly outrageous on the ethics committee,” Mr. Gingrich said. “I have been in a lot of tough fights. Liberal Democrats are allowed to take shots at me. If you are one of the most powerful figures in the most powerful country, guess what? You are in the middle of the arena.”

And the arena has been a tough venue for speakers in recent decades. In 1980, Republicans sought to make Thomas P. O’Neill a symbol of Democratic torpor. They ran a national advertisement with a cigar-chomping O’Neill look-alike driving a big car running on empty, saying Democrats were out of gas.

But the push against Mr. O’Neill was tame compared with what was to come. In mid-1988, Mr. Gingrich, then a rising power, put the spotlight on Speaker Jim Wright, focusing on large royalties from a book deal and other business dealings. A year later, Mr. Wright was gone, offering his resignation and warning of “mindless cannibalism” threatening to consume Congress.

Mr. Gingrich ultimately filled the speaker’s chair in 1995. But almost 10 years after he ousted Mr. Wright, Mr. Gingrich himself was out the door in 1998, resigning under pressure resulting from a surprise reversal in his party’s political fortunes. He was replaced by J. Dennis Hastert, who was spared assaults by Democrats who focused their aim mainly on his No. 2, Tom DeLay.

Now Mr. Gingrich is back, looking for the scalp of another speaker.

In his push against Ms. Pelosi, he has gone further than Republican leaders in the House, who have trod carefully around the idea of ousting Ms. Pelosi, saying they only want an inquiry into whether she was correct in her recollection of the C.I.A. briefing.

“Newt Gingrich is a force of nature,” said Representative Mike Pence of Indiana, the No. 3 Republican in the House, “but House Republicans really believe it is imperative that we have a thorough and immediate bipartisan investigation of the serious allegations that the speaker has leveled at the C.I.A.”

To Pelosi allies, it is laughable that Mr. Gingrich should be leading the charge against her, given his own history. “This is a person who was reprimanded by the House, fined $300,000 and forced to resign in disgrace,” said former Representative David E. Bonior, who in 1997 filed the initial complaint against Mr. Gingrich. “He should not be giving ethics lessons to anybody else.”

As for Ms. Pelosi, she said she would not be thrown off stride by the tactics of Mr. Gingrich, other Republicans or anyone else. “What we are doing,” she said, “is staying on our course and not being distracted from it in this distractive mode.”

Other recent speakers have made similar vows. The test for Ms. Pelosi will be whether she can keep her vow despite the onslaught by Republicans and a notable predecessor who himself found the job impossible to hold onto.