Former FBI agents are warning that FBI Director Christopher Wray has to be prepared to quit, should President Donald Trump assent over bureau objections to the release of a memo calling the FBI’s integrity into question.

The release of the memo, considered imminent, shows no signs of stopping, even as the leader of Democrats in the House called on its Republican author, Devin Nunes, to be removed from his chairmanship of the House intelligence committee. It was the latest move in an extraordinary episode that appears set to spark a crisis over the criminal investigation into Trump’s potential ties to Russia.

At the center of the storm is Wray, Trump’s hand-picked FBI director. Wray got his job after Trump fired James Comey last year for what Comey described as insufficient personal “loyalty” over the Russia investigation.

On Wednesday, Wray’s FBI publicly attacked Nunes’ memo for “material omissions of fact that fundamentally impact the memo’s accuracy.” Trump overriding Wray will immediately call Wray’s future in the Trump administration into question six month into his tenure.

Former FBI agents say that they hope Wray can remain in office, and pull Trump and House Republicans back from the precipice of what may be a pivotal moment in the bureau’s history. But they also say Wray needs to show his willingness to walk.

“Given the climate and the recent activities, going as far back as Director Comey’s departure, Wray definitely must be prepared to resign,” said Erroll Southers, a retired FBI special agent now at the University of Southern California.

“I don’t think the director has to resign. He should be prepared to publicly discredit this cherry-picked, fake memo and expose Nunes,” added former FBI counterterrorism special agent Ali Soufan. Soufan cited the bad blood between Director Louis Freeh and President Bill Clinton in the 1990s as a sign that the FBI can continue investigating a president despite their relationship collapsing.

But if Trump “wants to fire Wray, let him fire Wray, like Comey,” Soufan continued. “And then people in Washington should be prepared for a Saturday Night Massacre. Many honorable men and women should be prepared to resign, to walk out over this.”

With Wray under pressure, the FBI Agents Association, a support group 80 percent of whose members are active FBI special agents, praised him on Thursday for standing “shoulder to shoulder” with the FBI’s rank and file. It came right as CNN reported the White House is afraid Wray will quit.

“As Director Wray noted, FBI special agents have remained steadfast in their dedication to professionalism, and we remain focused on our important work to protect the country from terrorists and criminals—both domestic and international,” association president Thomas O’Connor said in a Thursday statement.

Nunes shows no signs of backing down, prompting Rep. Nancy Pelosi, the Democratic minority leader, to call Thursday for House Speaker Paul Ryan to remove Nunes from the intelligence committee on which she formerly served. “Congressman Nunes has abused his position to launch a highly unethical and dangerous cover-up campaign for the White House,” Pelosi charged.

“ Given the climate and the recent activities, going as far back as Director Comey’s departure, Wray definitely must be prepared to resign. ” — Retired FBI special agent Erroll Southers

But Nunes has the support of Trump, on whose transition team he served. Trump is widely expected to assent to the memo’s release as soon as Thursday, though Fox News is reporting it will come Friday. That is the day when the House of Representatives’ parliamentary rules compel Trump to register any objections to declassification of the memo the FBI considers fundamentally misleading.

Southers expects Wray’s tenure after the memo’s release to be “very tense. The pressure is going to continue mounting. I never thought I’d see the FBI deemed the enemy of the state by anyone, let alone people in this country,” he said.

Should Wray remain in office, Southers continued, “he’s going to have to be a rock going forward, making clear to people that his only objective [will be] to stay focused on the mission. Certain things will be out of his control, and that includes his future, as it relates to the president.”

As Mueller Moves Closer, Trump Takes Aim

Trump appears highly motivated to ignore the FBI’s objections. According to The Washington Post, Trump has told allies that the memo’s accusations will prompt him to “pus[h] out Rosenstein,” the deputy attorney general who is special counsel Robert Mueller’s overseer and a target of the Nunes memo. Though Rosenstein aided Trump in firing Comey in May, Trump has reportedly responded to Rosenstein’s requests for aid in staving off Nunes by asking if Rosenstein was “on my team.”

The senior Democrat on the Senate intelligence committee, Sen. Mark Warner, has warned firing Rosenstein, is a prelude to firing Mueller or hiring a new deputy attorney general to restrict Mueller’s inquiry—something Warner said last month “has the potential to be a constitutional crisis.”

Release of the memo, eagerly cheered by House Republicans and Fox News, is coming as Mueller’s probe shows signs of advancing to the White House door.

Mueller wishes to interview Trump himself and The New York Times reported Wednesday night that Mueller is interested in a lie Trump was involved in telling last summer that concealed the true purpose of a June 2016 meeting at Trump Tower attended by one of Trump’s sons, now-indicted campaign head Paul Manafort and son-in-law Jared Kushner. An intermediary had told Donald Jr. that a Russian attorney sought to provide damaging information on Hillary Clinton.

“ Many honorable men and women should be prepared to resign, to walk out over this. ” — Former special agent Ali Soufan

Mueller’s probe is an outgrowth of an FBI investigation that Nunes’ still-secret memo purportedly claims was tainted from the start. In batting back the FBI’s attack on his memo, Nunes confirmed that one of its claims concerns another right-wing bete noire: the salacious dossier, compiled by ex-British spy Christopher Steele, financed at first by Trump’s GOP rivals and then Democrats last year, alleging that Trump allies had been compromised by or complicit with the Kremlin.

“Top officials used unverified information in a court document to fuel a counterintelligence investigation during an American political campaign,” Nunes charged Wednesday, calling the FBI and Justice Department objections “spurious” and self-interested.

That’s a reference to a surveillance application submitted last year for Carter Page, a Trump campaign foreign policy aide with a history of proximity to Russian spies.

But according to ex-Justice Department attorneys who have been involved in the so-called Foreign Intelligence Surveillance Act (FISA) process, information from the Steele dossier could have played little more than a marginal role.

To obtain a surveillance warrant on a specific person under what is known as Title I FISA, a judge on a secret court must find the Justice Department and FBI have probable cause to believe their intended target is an agent of a foreign power. Showing that involves affiants describing the evidence underlying each of their arguments.

But Steele’s dossier cited proprietary and unnamed sources for his claims. While Justice Department lawyers are permitted to cite the FBI’s confidential sources before a FISA Court judge, they would not be in a position to explain why Steele’s unknown sources merit confidence. At most, attorneys say, Steele’s information could bolster submissions for which the FBI and Justice Department already had evidence.

“It’s appalling to see a president attack our nation’s law enforcement institutions that, in my experience, work diligently and tirelessly to protect our citizens, all the while striving to abide by the law,” said Josh Geltzer, an attorney in the Justice Department’s national-security division during the Obama administration.

Last-Minute Fights to Stop the Memo

Release of the memo appeared a foregone conclusion after Nunes prevailed in an internal committee vote Monday to force its release. As The Daily Beast first reported, Nunes dismissed FBI and Justice Department objections as a conflict of interest and elided a pointed question over whether he and his staff had colluded with the White House on a memo attacking Trump’s enemies—something Nunes has a history of doing and concealing.

In a last-minute attempt to derail the memo’s release, the House intelligence committee’s top Democrat, Adam Schiff, accused Nunes late on Wednesday of materially changing the memo’s contents after the committee voted to release it. Fellow panel Democrat Jim Hines had gotten Nunes to indicate during the contentious Monday vote that the document would not be changed, though Nunes stopped short of promising Hines that.

But a Nunes spokesman dismissed Democratic demands to withdraw the document. Republicans on the panel made only “minor edits to the memo,” spokesman Jack Langer asserted, such as “grammatical fixes and two edits” at the behest of the FBI and the Democrats. “To suggest otherwise is a bizarre distraction from the abuses detailed in the memo, which the public will hopefully soon be able to read for themselves,” Langer said.

“ It’s appalling to see a president attack our nation’s law enforcement institutions that work diligently and tirelessly to protect our citizens, all the while striving to abide by the law. ” — former Justice Department attorney Josh Geltzer

Democrats did not quantify the changes they say Nunes made to the secret document, but a committee source said they were neither cosmetic nor mitigated the risk of exposing counterintelligence-relevant information for the memo’s release. The changes, according to the committee source, also did not redress the FBI’s now-rebuffed criticism that the memo misstates the surveillance process it purports to describe.

The source also rejected Langer’s claim that Democrats had requested certain changes, saying that they consider the document “fundamentally flawed”—a position they now share with the FBI.

Yet the White House is signalling that those concerns emerge from what they consider hostile actors. Chief of Staff John Kelly rejected Rosenstein and Wray’s concerns about the memo during a White House meeting earlier this week, heralding a potential reckoning with the Justice Department, the FBI, and perhaps the two men themselves after the memo is released.

“We are at a very weird stage of our democracy,” said ex-FBI agent Soufan. “It’s not just about the FBI. It’s about loyalty to the president, or loyalty to the constitution. We are at a crossroads. We need to fight back. It’s probably the most important fight in modern American history.”