FBI Director Christopher A. Wray looks on during the International Conference on Cyber Security at Fordham University in New York. (Drew Angerer/Getty Images)

Long-simmering tensions between the President Trump-led Republican Party and federal law enforcement erupted into open battle Wednesday, with the FBI issuing an extraordinary public rebuke of a controversial memo that House Republicans and the White House are preparing to make public.

In a statement sent to reporters, the FBI says it has “grave concerns” about the memo, suggesting that it omits key facts and is thus inaccurate.

“As expressed during our initial review, we have grave concerns about the material omissions of fact that fundamentally impact the memo’s accuracy,’’ the FBI said.

The phrasing is as diplomatic as you would expect from government bureaucracy, but let's be clear: The FBI is essentially labeling this a partisan document that uses lies to undermine law enforcement. And by extension, it's accusing the White House of abdicating its responsibility to the American people by releasing it. The memo, which relies on classified information, alleges surveillance abuses against Trump campaign adviser Carter Page and was drafted by staff members of House Intelligence Committee Chairman Devin Nunes (R-Calif.).

Created by House Intelligence Committee Chairman Devin Nunes (R-Calif.), the four-page memo is critical of the Justice Department and the FBI's handling of the Russia investigation. (Victoria Walker/The Washington Post)

The FBI's statement was released shortly after Trump signaled that he would approve the release of the memo. Trump said after his State of the Union address Tuesday night that he would "100 percent” do it, and then White House Chief of Staff John F. Kelly said Wednesday morning that it would be released “pretty quick I think.”

Deputy Attorney General Rod J. Rosenstein and FBI Director Christopher A. Wray had privately pleaded with the White House not to release the document, arguing that it would set a dangerous precedent for releasing classified information and was essentially an inaccurate attack on the FBI. But with those warnings apparently going unheeded and the White House signaling that it would press forward, the FBI stepped up its campaign by releasing a public statement making the same case.

This represents a significant — if perhaps inevitable — showdown between Trump and his own appointees in the Justice Department. Trump fired FBI Director James B. Comey last year, has been public about his frustrations with Attorney General Jeff Sessions, and reportedly wants to get rid of Rosenstein (possibly with the aid of this memo), who oversees the Russia investigation following Sessions's recusal. The president has clashed with just about every leading member of federal law enforcement. Trump often demands or expects loyalty, and that has created almost ever-present conflicts with those involved with the Russia investigation, who generally are supposed to retain some degree of independence from the White House.

After delivering his State of the Union address on Jan. 30, President Trump told Rep. Jeff Duncan (R-S.C.) that he will "100 percent" release a memo alleging misconduct by the FBI. (The Washington Post)

But while these clashes have often occurred behind closed doors — only to be reported on days or even months later — the FBI has now publicly put the White House on notice about this memo, signaling that it and the Republican Party will own whatever results from its release. If the memo comes out and is later proved to be inaccurate, the FBI will be able to say: We told you so. The significance of taking a public stand suggests both desperation and resolute defiance. We've essentially just reached the next Defcon.

In the near-term, though, the effort is probably for naught — at least with Republicans in power. Republicans have shown over and over again that they give Trump the benefit of the doubt when it comes to his interactions with federal law enforcement officials. A recent Quinnipiac University poll found 83 percent of Republicans say the Russia investigation is a “witch hunt” against the president, while 12 percent say it's legitimate. And the FBI coming out publicly against the release of the memo is sure to strike Trump's supporters as further evidence that the FBI has something to hide here. Even if the FBI's motives are pure, it is basically relying on people to trust it. And Republicans trust Trump more.

It's a vicious cycle for law enforcement officials. But with their backs to the wall on Wednesday, they decided they would finally play their best remaining card.