(CNN) - House Speaker Nancy Pelosi is engaging in a "despicable, dishonest and vicious political effort" to withhold what she knew about the CIA's aggressive interrogation techniques, Newt Gingrich said Friday, in what amounts to the harshest criticism yet leveled at the California Democrat.
In an interview with ABC Radio, the former House Speaker said Pelosi flat-out "lied to the House" when she earlier claimed the CIA had never briefed her about the Bush administration's use of aggressive interrogation techniques including waterboarding.
"I think that the House has an absolute obligation to open an inquiry, and I hope there will be a resolution to investigate her. And I think this is a big deal. I don't think the Speaker of the House can lie to the country on national security matters," Gingrich said.
Pelosi has been under fire from critics who say that she was fully briefed on the techniques in 2002 and 2003. On Thursday, the California Democrat accused CIA officials of misleading her, reiterating an earlier claim that she was briefed on such techniques only once - in September 2002 - and that she was told at the time that the techniques were not being used.
Pelosi also said the briefing she received from the CIA was incomplete and inaccurate, and she called on the CIA to release a full transcript of the briefing. She also accused Republicans of jumping on reports of the briefings to cause a distraction.
"She is a trivial politician, viciously using partisanship for the narrowest of purposes, and she dishonors the Congress by her behavior," Gingrich also said in the blistering interview.
"Speaker Pelosi's the big loser, because she either comes across as incompetent, or dishonest. Those are the only two defenses," he continued. "The fact is, she either didn't do her job, or she did do her job and she's now afraid to tell the truth."