Democrats who spent weeks defending Speaker Nancy Pelosi (D-Calif.) after she accused the CIA of lying to lawmakers about its interrogation of suspected terrorists are going on offense as new details emerge about agency activities that were kept secret from Congress.

Two events have given new momentum to Democrats to shape debate on issues of CIA credibility: Last month, a band of House Intelligence Democrats released a letter to CIA Director Leon Panetta saying he had admitted that his agency regularly misled and concealed information from Congress. The letter was followed by a New York Times story Sunday indicating that former Vice President Dick Cheney instructed the CIA not to tell Congress about a secret counterterrorism program from 2001 until June 2009.

Armed with this new information, Democrats are finally getting their mojo back on an issue that Republicans have used to bash Pelosi since her May allegations against the CIA.

The fact that there is now evidence of the CIA misleading Congress “certainly shows that Republicans were being disingenuous and overly political,— one senior House Democratic aide said. “I think it turns the tables on the Republicans on this issue. Not that they’ll admit it.—

Intelligence Chairman Silvestre Reyes (D-Texas) is weighing a full committee investigation into whether the CIA broke the law by keeping information from Congress; he is gathering documents from Panetta to determine whether a probe is warranted. Many Democrats on the committee have pressed Reyes to hold a hearing on the matter.

Regardless of whether he convenes a hearing, Reyes signaled that the CIA is losing credibility in Congress.

“There’s a lot of frustration,— Reyes said Friday. “Certainly, we all recognize that there are issues, not with the hardworking men and women of the CIA, but with the way the Congress gets information — particularly with the last administration.—

On Monday, Pelosi urged the House and Senate Intelligence committees to determine what role Cheney had in the CIA concealing information from Congress.

“It behooves the committees to take whatever actions they believe are necessary to get more information on that subject, as to whether the intelligence community was directed by the vice president to create a program and intentionally withhold that information from Congress,— Pelosi said.

The committees also should find out “if the same intelligence community people were asked, Is there anything else we should know?’ [and] whether they said yes or whether they said no,— Pelosi said.

Key Republicans are also calling for a committee investigation into Cheney’s role in the CIA’s activities, although they aren’t letting Pelosi off the hook for her accusations against the agency.

“Investigate Cheney. I’m fine with that,— said Intelligence ranking member Pete Hoekstra (R-Mich.), who is skeptical that Democrats will follow through and said he was ignored when he called for a probe into Pelosi’s allegations. “The Democrats like to throw around the term investigation’ and then never do anything.—

Hoekstra said he “begged— Reyes to launch a CIA probe last year, when a federal investigation revealed the agency had lied to Congress about the 2001 shooting death of a Michigan missionary and her baby in Peru after their plane was misidentified as a drug smuggling aircraft.

House Republican Conference Chairman Mike Pence (Ind.) also offered support for an investigation into Cheney’s involvement in concealing the CIA counterterrorism program from Congress.

“Let me give you an absolute, categorical yes,— Pence said. He noted that House Republicans brought a resolution to the floor — and may do so again — that would have established a special panel within the Intelligence Committee to investigate Pelosi’s allegations that the CIA lied to Congress.

“The American people deserve to know whether the CIA lied to Congress or whether Members of Congress are lying to the American people,— Pence said.

Michael Steel, a spokesman for House Minority Leader John Boehner (R-Ohio), said there are still questions about what Pelosi knew of the use of harsh interrogation techniques following a private briefing by the CIA in September 2002.

“Does she have any evidence to back up her attacks? And if not, when will she apologize?— Steel asked.

Republican operatives also sought to keep a focus on Pelosi as the CIA scandal unfolds.

“The longer Democrats are talking and obsessing about the CIA, the more they are prolonging an already disastrous narrative for Nancy Pelosi and their party,— said Ken Spain, a spokesman for the National Republican Congressional Committee.

The White House offered a sympathetic nod to lawmakers frustrated with being kept in the dark by the CIA.

“The president believes that Congress should always be briefed fully and in a timely manner in accordance with the law. Those are his beliefs as it relates to any of those programs,— White House Press Secretary Robert Gibbs said Monday.

But Gibbs declined to say whether President Barack Obama had been briefed on the program and urged lawmakers not to dwell on the past. “Our efforts are better focused looking forward than looking back,— Gibbs said.