The Intelligence Committee had voted to send the White House a different version of that memo for review and potential release.
"It is long overdue that you, as Speaker, put an end to this charade and hold Congressman Nunes and all Congressional Republicans accountable to the oath they have taken to support and defend the Constitution, and protect the American people," Pelosi, D-Calif., wrote Ryan, R-Wisc.
"The integrity of the House is at stake," she wrote.
Rep. Adam Schiff of California, the ranking Democrat on the Intelligence Committee, has called the memo that Nunes wants to release little more than a "conspiracy theory."
The memo, according to Schiff, suggests that "a cabal of senior officials within the FBI and the Justice Department were so tainted by bias against President Trump that they irredeemably poisoned the investigation."
Read Pelosi's full letter to Ryan below:
The Honorable Paul D. Ryan
Speaker of the House of Representatives
H-232, United States Capitol
Washington, D.C. 20515
Dear Mr. Speaker:
The decision of Chairman Nunes and House Republicans to release a bogus memo has taken the GOP's cover-up campaign to a new, completely unacceptable extreme.
Both the DOJ and FBI oppose releasing the Nunes memo. As the Department of Justice warned, the public release of the memo would be an "unprecedented action" and "extraordinarily reckless." The FBI also expressed that the agency has "grave concerns about material omissions of fact that fundamentally impact the memo's accuracy."
It has now come to our attention that Congressman Nunes deliberately and materially altered the contents of the memo since it was voted on by the House Republicans. This action is not only dangerous, it is illegitimate, and violates House rules.
From the start, Congressman Nunes has disgraced the House Intelligence Committee. Since pledging to recuse himself from the Trump-Russia investigation, Congressman Nunes has abused his position to launch a highly unethical and dangerous cover-up campaign for the White House.
Congressman Nunes' deliberately dishonest actions make him unfit to serve as Chairman, and he must be removed immediately from this position.
House Republicans' pattern of obstruction and cover-up to hide the truth about the Trump-Russia scandal represents a threat to our intelligence and our national security. The GOP has led a partisan effort to distort intelligenceand discredit the U.S. law enforcement and intelligence communities.
It is long overdue that you, as Speaker, put an end to this charade and hold Congressman Nunes and all Congressional Republicans accountable to the oath they have taken to support and defend the Constitution, and protect the American people.
The integrity of the House is at stake. We look forward to your immediate action on this subject.