Rep. Adam B. Schiff (D-Calif.) said on Jan. 29 that a vote by the House Intelligence Committee to release documents alleging missteps by the FBI in its Russia probe marked a “very sad day.” (The Washington Post)

Early this month, FBI Director Christopher A. Wray and Deputy Attorney General Rod J. Rosenstein trekked to Capitol Hill in a last-ditch effort to avoid giving Republican lawmakers access to intelligence they considered so sensitive that it could not leave their control.

House Intelligence Committee Chairman Devin Nunes (R-Calif.) had been agitating for information — which included investigative documents, interviews with top FBI officials and texts between FBI employees — for months as part of his investigation into the Justice Department’s handling of the Russia investigation. Now, he was threatening to hold Justice officials in contempt. The two law enforcement leaders hoped House Speaker Paul D. Ryan (R-Wis.) might be more sympathetic to their concerns.

Rosenstein did most of the talking as the two men pressed their case in a closed-door meeting, urging the speaker to let the Justice Department withhold at least some documents, according to people familiar with the exchange. Ryan, however, was unmoved. Nunes’s committee, he argued, routinely deals in sensitive, raw intelligence, and this case was no different, the people said.

The episode would prove a revealing skirmish between the Hill and the Justice Department in an increasingly acrimonious war over the Russia investigation. Current and former law enforcement officials say the feuding — which they say seems driven in some measure by a GOP effort to discredit the Russian investigation — threatens to expose sensitive sources and methods that could be exploited by foreign adversaries, and curtail intelligence-sharing with some of the United States’ closest allies, including Britain.

House Intelligence Committee Chairman Devin Nunes (R-Calif.) is the primary driver behind a four-page memo critical of the Justice Department and FBI. (Susan Walsh/AP)

Nunes ultimately used the information he obtained to create a four-page memo critical of the Justice Department and the FBI. And to the dismay of Democrats and various intelligence and law enforcement officials, he and his Republican colleagues are taking steps to release it.

On Monday, Nunes’s committee voted on party lines to authorize its release, which gives the White House up to five days to intervene before it becomes public.

What exactly the memo says — and how significant it is in showing any alleged wrongdoing at the Justice Department and FBI — are matters of intense debate.

Republicans who have seen the document say it draws on Justice Department and FBI documents and information shared by informants and whistleblowers, and it looks at who made decisions on surveillance during the campaign and what shaped those decisions. It raises particular questions, they said, about an Oct. 19, 2016, application to the Foreign Intelligence Surveillance Court to conduct surveillance on former Trump campaign adviser Carter Page.

It is unclear to what extent information in a controversial dossier — which mentioned Page — played a role in that application, though some of its author’s work was incorporated. The dossier was produced by Christopher Steele, a former British intelligence officer hired by Fusion GPS, a Washington opposition research firm. Fusion was hired by political actors to research Donald Trump — first, the conservative media outlet Washington Free Beacon, and then, before Steele was brought on board, Hillary Clinton’s campaign and the Democratic National Committee.

The court was apparently not told of the dossier’s Democratic Party funding, according to a person familiar with the memo.

Conservative commentators, lawmakers and the president himself are harshly criticizing the FBI. From the FISA memo to a "secret society," here are some of their claims. (Jenny Starrs/The Washington Post)

That assertion could provide conservatives ammunition to criticize the Russia investigation and lay the groundwork to possibly discredit whatever conclusions those working on it reach.

“Day after day, each individual dot on the wall reinforces a pattern that is not helpful to the left,” said former House speaker Newt Gingrich, rattling off a list of alleged wrongdoing by the Justice Department and FBI.

The court process to obtain such a surveillance warrant is robust, and Page had been on the FBI’s radar for years — long before agents were in possession of the dossier. The application cited, among other things, contacts that Page had with a Russian intelligence operative in New York City in 2013, which had surfaced in an earlier case, U.S. officials said. In addition, the application said Page had other contacts with Russian operatives that have not been publicly disclosed, according to the officials who, like others, spoke on the condition of anonymity to discuss sensitive matters.

Republicans, meanwhile, continue to maintain that mistakes were made in that process, but the party has divisions over how meaningful they are.

Rep. Jim Jordan (R-Ohio) suggested that the memo would be explosive: “We get this memo out there, and people will see, the fix was in.” Another Republican who has seen it said it might not be the smoking gun that conservatives have described. Rep. Mark Sanford (R-S.C.) said that while he has received more phone calls from constituents on the document than he did on the government shutdown, he largely attributed that uproar to cable news coverage of it.

“I will let people draw their own conclusions,” he said. “There is certainly damaging information.”

Though public fighting over the memo has intensified in recent weeks, its gen­esis can be traced back to last summer, when the House Intelligence Committee issued subpoenas to the FBI and Justice Department for documents related to the dossier.

Nunes and other Republicans were at the time keenly interested in the role the dossier played in fostering what is now special counsel Robert S. Mueller III’s investigation into whether the Trump campaign coordinated with the Kremlin to influence the 2016 election.

Nunes and other key Republicans on the Hill sent aides or went themselves to review documents at the Justice Department, and Nunes’s senior committee staffers compiled a comprehensive review of points of concern. They focused on the information the agencies used to prompt applications for warrants, Republicans familiar with their work said. Those analyses eventually became the memo.

The Justice Department has suggested publicly that Nunes himself did not review the materials that formed the basis for the memo — apparently instead relying on staff to brief him. One key player is a Justice Department alum: Kashyap Patel, who had worked as a prosecutor in the Justice Department’s National Security Division and was famously berated by a federal judge in Texas over his failure to wear a suit and tie.

Patel has reviewed materials from the Justice Department and was one of two staffers who made a trip to London to try to talk to Steele, according to people familiar with the matter.

Jack Langer, spokesman for the House Permanent Select Committee on Intelligence (HPSCI), said many committee members and staff members worked on it.

“The memo was the result of many hours of work by committee members and numerous staff members, and for The Washington Post to publish a hit piece singling out one staffer is a real low in journalism,” Langer said.

Nunes’s probe seemed to intensify in December, as the House Ethics Committee dropped its investigation of him, and The Washington Post and the New York Times reported on anti-Trump texts exchanged between members of Mueller’s team. In late December, Nunes excoriated the Justice Department for failing to give him access to all the documents he said he needed, and the next month, Wray and Rosenstein made their appeal to Ryan.

On Jan. 18, Nunes’s committee — on a motion from Rep. Peter T. King (R-N.Y.) — voted to make the memo available to all House members to read in a secure facility in the basement of the Capitol. Members were initially split on whether it should be publicized. That would soon change.

That afternoon, the House Freedom Caucus — a GOP group that counts a few dozen hard-line conservatives as members — spoke by phone with President Trump about the impending government shutdown. As they discussed possible spending deals, the group’s chairman, Rep. Mark Meadows (R-N.C.), brought up the memo with the president as members called for its release, according to people familiar with the call.

The caucus that night publicly launched a campaign to have the document revealed, and the hashtag “ReleaseTheMemo” soon spread widely on Twitter.

Democrats and the Justice Department pushed back. Last week, the department sent a letter to Nunes, saying officials there had yet to see the document and that it “would be extraordinarily reckless for the Committee to disclose such information publicly without giving the Department and the FBI the opportunity to review the memorandum and to advise the HPSCI of the risk of harm to national security and to ongoing investigations that could come from public release.”

A Justice Department spokeswoman declined to comment Monday.

Rep. Adam B. Schiff (Calif.), the ranking Democrat on the House Intelligence Committee, said in an interview last week that the release could “compromise sources and methods” of the intelligence community and damage U.S. relations with intelligence partners around the world. He said Democrats would have to consider releasing their own document dispelling any myths or confusion that their Republican counterparts’ memo might create — though the committee voted Monday along party lines against releasing a second Democratic memo on the issue.

Wray, the FBI director, has since seen the memo, but it was unclear whether the Justice Department remained opposed to its release. Schiff said that Wray “raised concerns” about the memo after viewing it and that he asked the committee to allow him to brief the members before voting on its release. They did not do so, he said.

On Wednesday, White House Chief of Staff John F. Kelly relayed to Attorney General Jeff Sessions that he supported the document’s release. Deputy White House press secretary Raj Shah said Monday on CNN that if Nunes’s committee voted to make the memo public, the White House would conduct a national security review, but he suggested the Justice Department would not be weighing in.

“The Department of Justice doesn’t have a role in this process,” he said.

William Kristol, editor at large of the Weekly Standard and a conservative Trump critic, said: “It’s pretty astonishing to have members of Congress and fairly serious commentators clamoring for the release even as Trump’s Justice Department says they should wait for a full review. It’s a distressing sign that the irresponsibility and conspiracy theorizing on the right is not just on the far right but among top people.”

The president has not yet seen the memo but has a “bare-bones understanding” based primarily on press coverage, a White House aide said. He has told advisers he supports the release of the memo and believes it could help show the public how biased the FBI and the special counsel investigation have been against him, two people familiar with his thinking said. Counselor to the president Kellyanne Conway said Monday that Trump “would err on the side of transparency.”

“That is his predilection: to release it,” one senior White House adviser said. “But he won’t decide it until he sees it.”

That could happen by week’s end.

Devlin Barrett, Josh Dawsey, Tom Hamburger, Shane Harris, Sari Horwitz, Carol D. Leonnig and Philip Rucker contributed to this report.