The top Democrat on the House Intelligence Committee said the memo the White House is reviewing isn't the one the committee Republicans voted to release.
The House Intelligence Committee sent the White House a different version of a classified memo about the Trump-Russia investigation from the one that committee Republicans voted to release to the public, and it should be withdrawn immediately, the committee's top Democrat said Wednesday night.
The committee voted Monday to release the memo, which was prepared by Republicans, on a straight party-line vote. The memo is under White House review; the final decision on whether to make it public rests with President Donald Trump.
Republicans who have seen the memo say it shows that the FBI relied on an opposition research dossier paid for by Democrats to obtain a warrant to conduct secret surveillance on an aide to Donald Trump's presidential campaign; Democrats who have seen the memo say it is an inaccurate and misleading attack on the investigation led by special counsel Robert Mueller designed to undermine the FBI.
In an unusual statement that appeared to be part of a last-ditch lobbying campaign designed to get the White House to reconsider releasing the memo, the FBI warned Wednesday it has "grave concerns" about the memo and agreed that the document contains "material omissions of fact that fundamentally impact the memo's accuracy."
Related: FBI urges White House not to release GOP Russia-probe memo
Rep. Adam Schiff of California, the Intelligence Committee's ranking Democrat, said in an open letter Wednesday night to the committee's chairman, Republican Devin Nunes of California, that he and other Democrats on the panel had since learned that the version of the memo that was sent to the White House isn't the same memo the committee voted to release on Monday.
Schiff described the differences in general as "substantive" and "material" alterations that committee members "were never apprised of, never had the opportunity to review, and never approved." That means "there is no longer a valid basis for the White House to review the altered document," he wrote.
Jack Langer, a spokesman for Nunes, confirmed that the memo had been edited, but he told NBC News that the changes included "grammatical fixes and two edits requested by the FBI and by the Minority themselves," referring to committee Democrats.
"The vote to release the memo was absolutely procedurally sound, and in accordance with House and Committee rules," Langer said. "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."
But a senior Democratic source on the Intelligence Committee disputed that account, telling NBC News that the changes weren't "cosmetic."
"Instead, they try to water down some of the majority's assertions," the source said.
In his letter, Schiff wrote that the changes prove that the committee's Republican majority "no longer stands by the representation it has made to House Members in its original document and felt it necessary to deceive Committee Members during Monday's vote."
He pointed to an exchange during the committee's deliberations between Nunes and Rep. Jim Himes, D-Conn., saying Nunes promised Himes that the memo wouldn't be changed before it was sent to the White House.
According to a transcript of the hearing that was made public Wednesday, Himes pressed Nunes to clarify whether the final version of the memo, if it were released to the public, would be "word for word" the same document that the committee reviewed or whether it would be "redacted or altered in any way."
According to the transcript, Nunes responded: "We will send the content over to the White House, and the president has five days to either agree with us that it should be made public, or the president could say that he does not want it made public."
Schiff called that response "misleading" Wednesday night — an assessment that Himes agreed with.
"In a formal meeting, I asked Chairman Nunes not once, but twice, if his memo would be released precisely as we reviewed it," Himes said on Twitter. "He said yes. Then altered it."
Senate Democratic leader Chuck Schumer of New York went further, accusing Nunes in a statement Wednesday night of working to "undermine the rule of law and interfere with the Russia probe" and calling on House Speaker Paul Ryan, R-Wis., to "put an end to this charade once and for all." He didn't suggest how Ryan could do that.
Two administration officials told NBC News that it was likely that the memo would be released Thursday. Officials said it was possible that the public version of the memo could include redactions of sensitive information, but Justice Department officials said the issues it raised were so highly classified that they might not be in a position to point out errors or misleading statements.
There was no immediate reaction from the White House late Wednesday.