Schiff and Nunes have been bitterly divided over the memo, which the House Intelligence Committee voted along party lines Monday to release to the public, provided Trump does not block the move.
Schiff charged that the memo was "secretly altered" after that, and that Democrats were only "belatedly" given a chance Wednesday night to see the altered version that was sent to the White House. He said it included changes that members "were never apprised of, never had the opportunity to review, and never approved."
A spokesman for the committee's Republican majority said the changes to the memo were "minor edits," such as grammatical changes, "and two edits requested by the FBI and by the minority themselves."
The spokesman defended the memo's release as "procedurally sound," adding that "to suggest otherwise is a bizarre distraction from the abuses detailed in the memo."
A senior Democratic committee official disputed the suggestion that Democrats had asked for any of the changes, describing them as "not cosmetic" but attempts "to water down some of the majority's assertions."
"It is clear that the majority is no longer fully comfortable with what it has represented to House members," the Democratic official said. "The majority has no choice but to restart the process in a transparent manner."
Trump is widely expected to approve the memo's release, potentially as early as Thursday, despite the protestations of Democrats and several senior law enforcement officials. He told a lawmaker Tuesday night following his State of the Union address that he plans "100 percent" to release the memo, and his chief of staff, John F. Kelly, said early Wednesday that he expected the memo would be made public "pretty quick."
Those statements prompted the FBI to issue a rare, unsigned statement Wednesday, citing "grave concerns" with inaccuracies and omissions in the four-page document written by GOP staffers on the Intelligence Committee. Nunes shot back at the FBI and Justice Department, charging that it was "no surprise" to see them "issue spurious objections" to the document. "It's clear that top officials used unverified information in a court document to fuel a counterintelligence investigation during an American political campaign," he added.
The memo alleges that the former British spy who wrote a dossier, Christopher Steele, passed bad information to the FBI — though people familiar with the document said it does not determine whether he did so intentionally or by mistake. The memo alleges that the information was used in an application to conduct surveillance on former Trump campaign adviser Carter Page, according to people familiar with the matter. Officials familiar with the Page case have said that Steele's information represented a small part of the secret court document.
Before Democrats identified the "material changes" they allege Nunes made to the memo, they were already accusing Republicans of coordinating with the White House to publicize it. The moves are an "effort to circle the wagons around the White House and distract from the Russia probe," Schiff said during the House Intelligence Committee's Monday night business meeting, according to a newly released transcript.
Leading Democrats doubled down on such charges Wednesday night, after Schiff released his letter to Nunes.
"It's clear that Chairman Nunes will seemingly stop at nothing to undermine the rule of law and interfere with the Russia probe," Senate Minority Leader Charles E. Schumer (D-N.Y.) said in a statement. He accused Nunes of being "willing to carry the White House's water . . . and now to mislead his House colleagues."
"If Speaker Ryan cares about the integrity of the House or the rule of law, he will put an end to this charade once and for all," Schumer said.