Updated

Despite mounting criticism of a proposed covert CIA program to have teams capture or kill targeted Al Qaeda leaders, Democrats sounding the alarms say they're more concerned that they weren't told about it than they are about the proposal itself.

FOX News has confirmed that the long-dormant idea, hatched in the wake of the Sept. 11 attacks, was brought to CIA Director Leon Panetta's attention this year by a CIA unit that was considering advancing it.

An official with knowledge of the plan told FOX News, "there was thought being given to moving toward a more operational status," which would involve training. For that reason, the unit recommended Panetta brief Congress, the official said.

That briefing, at which Panetta informed lawmakers he was terminating the proposal, triggered accusations from House Democrats that the CIA had "concealed" information from them all along.

But at least a few of the lawmakers who raised those concerns in a letter last month to Panetta are pointing to the lack of oversight as the main issue of contention. They're not saying unequivocally that the idea of CIA teams taking out Al Qaeda leaders the old fashioned way is a bad one.

"I don't think it's fair to say that under no circumstances could the CIA be allowed to hit first at an Al Qaeda target," Rep. Adam Smith, D-Wash., told FOXNews.com, though he declined to address the specifics of the program Panetta described to lawmakers. "But I would say that you've got to be extraordinarily cautious about those situations."

Smith noted that the United States already uses Predator drones to kill Al Qaeda operatives.

He said oversight is his chief concern.

"They don't need to tell us every time they send an agent somewhere, but there are certain covert programs they need to notify us about," he said.

An aide to Rep. Jan Schakowsky, another co-signer to the Panetta letter, also said oversight was the main concern for the Illinois Democrat.

And another Democratic aide said that Rep. Mike Thompson, D-Calif., yet another co-signer, feels the same way.

"The issue is that this was done without congressional oversight," the aide said. "(Thompson) can't think of anyone in the House who would be opposed to taking out top Al Qaeda leaders."

Sen. Russ Feingold, D-Wis., raised "deep concerns" about the proposed program itself in a written statement Monday, but did not elaborate. He said he had conveyed those concerns and a request for an investigation to President Obama.

But the political firestorm over the CIA plan, the latest in a series of controversies surrounding the way the Bush administration handled the war on terror, is rooted more in complaints that Congress should have been in on the ground floor.

The official with knowledge of the CIA plan said Panetta realized "there would be heat" when he brought the issue to Congress.

"He understood the political context in which this whole thing unfolded," the official said. "When something's not adequately briefed to Congress, unlike a fine wine, it doesn't get better with age."

CIA spokesman George Little said Panetta had no regrets about briefing Congress. But he reiterated that the plan never got off the ground.

"The program he killed was never fully operational and never took a single terrorist off the battlefield," Little said. "Those are facts he shared with Congress. We've had a string of successes against Al Qaeda and other terrorist groups, and that program didn't contribute to any of them."

Rep. Silvestre Reyes, D-Texas, chairman of the House intelligence committee, recently told FOX News that he is reviewing information and that he asked the CIA for additional documents. He said there is no plan yet for an investigation, though he would nevertheless welcome one because it might shed light on allegations by House Speaker Nancy Pelosi that the CIA lied to her.

The prior Pelosi comments, combined with new allegations that former Vice President Dick Cheney told the CIA to keep a lid on the Al Qaeda plan, cast the current debate in a strictly political light, Republicans say.

Rep. Pete Hoekstra, R-Mich., ranking Republican on the House intelligence committee, said Democrats are using the Cheney angle to politicize the situation. He said there should be no objections to such efforts to target Al Qaeda leaders, something that has been attempted vigorously since 2001.

Jennifer Millerwise Dyck, a former CIA spokeswoman, said the CIA had no obligation to brief Congress either.

"It's been nothing more than a concept. It was never even built into a usable capacity and certainly did not rise to the threshold of something that needed to be briefed to Congress," she said. "If Congress were to be briefed on every single idea or concept that came across the minds of people at CIA ... they might as well be embedded in the agency."

Rep. Rush Holt, D-N.J., disagreed.

"No CEO should be allowed to audit his own books, nor should the U.S. intelligence community be able to decide for themselves who are the bad guys and how will we go at them," he said. "You need oversight."

FOXNews.com's Judson Berger and FOX News' Jennifer Griffin, Justin Fishel and Chad Pergram contributed to this report.