WASHINGTON -- Before White House chief of staff Denis McDonough came to brief Senate Democrats on Thursday afternoon, Majority Leader Harry Reid (D-Nev.) had a little pep talk with his flock. Every Tuesday, during the weekly caucus lunches, he said, you all gripe and moan about the White House. But then when the White House comes by, there's never a peep.

The talk may not have been necessary. The White House's briefing to Democrats on immigration Thursday erupted instead into a confrontation over the Senate's classified torture report, Senate sources told The Huffington Post.

Sen. Dianne Feinstein (D-Calif.), the chair of the Senate Intelligence Committee, waited for the immigration discussion to end and then pulled out a prepared speech that she read for five or six minutes, making the case for the release of the damning portrayal of America's post-9/11 torture program.

"It was a vigorous, vigorous and open debate -- one of the best and most thorough discussions I've been a part of while here," said Sen. Chris Coons (D-Del.).

Sen. Jay Rockefeller (D-W.Va.), who served as intelligence committee chair before Feinstein, was furious after the meeting, and accused the administration of deliberately stalling the report.

“It’s being slow-walked to death. They’re doing everything they can not to release it," Rockefeller told HuffPost.

"It makes a lot of people who did really bad things look really bad, which is the only way not to repeat those mistakes in the future," he continued. "The public has to know about it. They don’t want the public to know about it."

As negotiations continue, Rockefeller said Democrats were thinking creatively about how to resolve the dispute. "We have ideas," he said, adding that reading the report's executive summary into the record on the Senate floor would probably meet with only limited success. "The question would be how much you could read before they grabbed you and hauled you off."

Besides Rockefeller, Sens. Martin Heinrich (N.M.), Ron Wyden (Ore.), Mark Udall (Colo.) and Mark Warner (Va.) all spoke up in defense of Feinstein, a source with knowledge of the situation said.

Senate Democrats have for years been pursuing an accounting of the acts committed in the name of the United States after the Sept. 11 attacks. Having finished preparing a 6,000-page report, Democrats are now locked in a struggle with the White House over releasing even a redacted summary.

Feinstein had hoped to release the summary during the summer, but has clashed with the White House over the use of aliases for CIA officials mentioned in the report.

Maine Sen. Angus King, an independent who caucuses with Democrats and sits on the intelligence committee, said there was a "good discussion" with McDonough on Thursday, but declined to get into specifics.

"I don't know if you'd call it progress," he told HuffPost.

Time is becoming a critical issue with regard to the report, as Republicans prepare to take control of the Senate in January. At that time, Sen. Richard Burr (R-N.C.) will replace Feinstein as head of the intelligence committee.

“I’m concerned that there’s not a whole lot of sand left in this hourglass,” said Heinrich. "Until this report is unclassified in a way that doesn't expose people's identity, but where you can understand the narrative, our work will not be done. And we're not there yet."

Heinrich, a member of the intelligence committee, compared the report to a story, arguing that it is impossible to follow without aliases or pseudonyms to guide a reader.

"If you take all the names out of a novel, it becomes very hard to understand that novel's narrative arc," he said. "We don't need people's real names, but we need to understand why decisions were made, what decisions were made and what the ramifications are."

Feinstein declined to discuss the meeting with reporters Thursday. "I ain't talkin'," she said.

Rockefeller said the administration's unwillingness to use aliases reflects a broader contempt for congressional oversight.

"The White House doesn't want to release this. They don't have to. And all we do is oversight, and they've never taken our oversight seriously," he said. (He then added that he did allow for one exception, the Church Committee.) "Under Bush there was no oversight at all. Remember the phrase, 'Congress has been briefed'? What that meant was that I and our chairman [...] and two comparable people in the House had met with [former Vice President Dick] Cheney in his office for 45 minutes and given a little whirley birdie and a couple charts."

"They had a specialty for being unforthcoming in our efforts at oversight," he added, "and therefore there is no incentive for them to change their behavior."

Democrats aren't the only ones who want to see the report released. A number of Republicans, most of whom opposed the so-called "enhanced interrogation" techniques used at Guantanamo Bay and other facilities, also say America needs to come clean in order to restore its moral standing.

Sen. John McCain (R-Ariz.), who was himself tortured while a prisoner of war in North Vietnam, said he's been in regular talks with Feinstein on the issue and agrees that the White House should release the document.

"I support her efforts," he told HuffPost. "I think the American people should know."

Asked if the report was likely to emerge, McCain said: "That is going to be up to Dianne Feinstein. She can get it released if she wants to, but she's not happy with the amount that's been redacted."

The breakdown in negotiations came just days after Feinstein appeared optimistic about the report’s release, telling reporters that negotiations were progressing and the report would likely be available to the public within a few weeks.

“We are down to essentially one item in the redaction,” Feinstein said Tuesday. “It happens to be a very sensitive and important item.”

But Feinstein’s optimism didn’t make it to midnight. At a meeting that same evening, senate and White House negotiators found they were much further apart than originally thought.

Despite a committee vote in April to declassify the report’s 500-page executive summary, the document’s release has been hamstrung for months by disputes over information that the White House and CIA want to keep secret.

The crux of that dispute lies with the committee’s use of pseudonyms, which are used throughout the report to refer to CIA personnel involved in the program. Although the committee says it's taken adequate precautions to ensure those personnel are not identified, the CIA says its agents’ true identities could easily be deduced through other information in the report-- which could put current clandestine officers and operations at risk.

“There are senior CIA officials who are named without redaction throughout the SSCI study. But there are others whose identities are not revealed -- for good reason,” said CIA spokesman Ryan Trapani. “There is a reasonable possibility that these officers -- many of whom are currently serving with CIA -- would be subject to threats and possible violence if their identities were revealed.”

The agency argues that while the names of the agents are not revealed, other information included in the report could easily lead the public and members of the press to discern who the panel is talking about.

“Making public pseudonyms associated with such individual officers, as well as dates, locations and other identifying information related to those officers, dramatically increases the likelihood that they will be exposed and potentially subject to threats or violence,” Trapani continued. “A pseudonym itself is little protection from exposure when a host of other information about that officer is made available to the public through the report and will likely be seen by adversaries and foreign intelligence services.”

But Heinrich dismissed that argument.

"For decades, every oversight report we've ever done has used either aliases or pseudonyms, because they protect people's identity," he said. "So I think that's very weak ground to stand on."