WASHINGTON - President Donald Trump authorized the release Friday of a GOP memo alleging surveillance abuses by the FBI, intensifying a fight between the White House and Republican lawmakers, on one side, and the nation's top law enforcement agency over claims that the FBI hid the political motivations of a key figure supplying it information in the case.

Trump approved release of the memo without redactions Friday morning. He told reporters in the Oval Office: "I think it's a disgrace what's happening in our country. . . . A lot of people should be ashamed of themselves and much worse than that."

The FBI has said it has "grave concerns" that the contents of the memo leave out important details and create an inaccurate portrait of its work.

The four-page, newly declassified memo written by the Republican staffers for the House Intelligence Committee said the findings "raise concerns with the legitimacy and legality of certain [Justice Department] and FBI interactions with the Foreign Intelligence Surveillance Court (FISC)." It cites "a troubling breakdown of legal processes established to protect the American people from abuses related to the FISA process," a reference to the Foreign Intelligence Surveillance Act.

The memo alleges that a surveillance warrant was obtained and renewed on a former Trump campaign adviser, Carter Page, with information from an individual with an anti-Trump agenda.

It accuses officials who approved the surveillance applications - a group that includes then-FBI Director James Comey, his deputy Andrew McCabe, then-Deputy Attorney General Sally Yates and current Deputy Attorney General Rod Rosenstein - of signing off on court surveillance requests that omitted key facts about the political motivations of the person supplying some of the information, Christopher Steele, a former intelligence officer in Britain.

The memo says Steele "was suspended and then terminated as an FBI source for what the FBI defines as the most serious of violations - an unauthorized disclosure to the media of his relationship with the FBI.'' The memo argues that Steele's contacts with reporters in the fall of 2016 "violated the cardinal rule of source handling - maintaining confidentiality - and demonstrated that Steele had become a less than reliable source for the FBI."

The government website housing the memo, docs.house.gov, crashed soon after the document was posted, apparently overwhelmed by users clamoring to read it.

The memo is not an intelligence document and reflects information the committee has gathered, which Democrats, the FBI and Justice Department have criticized as incomplete and misleading. Law enforcement officials have said they often rely on information from people with grudges or agendas but that investigators are expected to check the accuracy of any claims before seeking a warrant.

Current and former law enforcement officials said before the release that a major concern inside the FBI is that the rules governing classified information would impede their ability to respond to the memo's accusations once it became public.

The Justice Department and the FBI did not immediately comment after the memo's release Friday.

In September 2016, according to the memo, Steele admitted that he was "desperate that Donald Trump not get elected and was passionate about him not being president" in a conversation with Bruce Ohr, a Justice Department official.

At the time, Steele was researching possible Trump ties to Russia on behalf of Fusion GPS, a Washington, D.C., firm that also hired Ohr's wife to do Russia-related research. Fusion GPS was initially hired in late 2015 by a conservative website funded by a major GOP donor who wanted research done on Trump's business history.

Then, in spring 2016, Fusion GPS was hired by a lawyer representing the Hillary Clinton campaign and the Democratic National Committee to continue researching Trump. After the Democrats starting paying Fusion GPS, the firm hired Steele.

The memo charges that law enforcement officials vouched for Steele as someone who had provided valuable information in an earlier corruption probe involving FIFA, the world soccer organization, but that they did not tell the court about his political views regarding Trump.

"While the FISA application relied on Steele's past record of credible reporting on other unrelated matters, it ignored or concealed his anti-Trump financial and ideological motivations,'' the memo states.

Bill Priestap, an FBI executive, said the work of corroborating Steele's allegations against Page was in its "infancy" at the time of the first FISA application, and McCabe told the committee in December that "no surveillance warrant would have been sought from the [Foreign Intelligence Surveillance Court] without the Steele dossier information," according to the memo.

After the FBI terminated Steele as a source, an internal FBI report assessed that Steele's information had been "only minimally corroborated," the memo said.

Friday morning, the president tweeted in anticipation of the memo's release, saying: "The top Leadership and Investigators of the FBI and the Justice Department have politicized the sacred investigative process in favor of Democrats and against Republicans - something which would have been unthinkable just a short time ago." He added: "Rank & File are great people!"

California Rep. Adam Schiff, the top Democrat on the House Intelligence Committee, tweeted in response: "No, Mr. President it's worse than that. The country's top elected leader has agreed to selectively and misleadingly release classified info to attack the FBI - that's what would have been unthinkable a short time ago."

The memo has been the subject of intense debate in Congress, but the fight ratcheted up this week when the House Intelligence Committee voted along party lines to make the document public under a process that gives the president up to five days to block its release. The committee Republicans also voted not to release a Democratic rebuttal memo, saying they would allow that document to be made public in the future.

It is highly unusual for the White House and the FBI to be publicly at odds over a matter of national security, and it is unclear what impact the disagreement might have on the standing of FBI Director Christopher Wray and Rosenstein, two Trump appointees who went to the White House on Monday in an unsuccessful bid to urge that the memo not be released.

Law enforcement officials have expressed fear that Trump may try to use the memo's release as justification to fire Rosenstein, who is overseeing Special Counsel Robert Mueller and the Russia interference probe.

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The Washington Post's Philip Rucker contributed to this report.