Schiff said the memo on alleged Foreign Intelligence Surveillance Act abuses is designed to suggest 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."

A fiercely disputed memo sent to President Donald Trump to be publicly released is little more than a "conspiracy theory," said Rep. Adam Schiff , ranking Democrat on the House Intelligence Committee, in an op-ed for The Washington Post .

House Republicans on the committee voted Monday to send the still-classified memo to Trump, over the warnings of Justice Department officials that doing so would be "extraordinarily reckless."

Schiff argued that releasing the memo via an "obscure rule" in the present political circumstances would increase the "risk of a constitutional crisis." He said it could galvanize Trump to fire special counsel Robert Mueller, who is investigating possible ties between the Trump presidential campaign and Russia, or Deputy Attorney General Rod Rosenstein, who appointed Mueller.

On Wednesday, the FBI said it had "grave concerns" about the accuracy of the memo. House Intelligence Committee Chairman Devin Nunes, R-Calif., responded, saying "It's no surprise to see the FBI and DOJ issue spurious objections to allowing the American people to see information related to surveillance abuses at these agencies."

Nunes did not immediately respond to CNBC's request for comment.

The White House has yet to guarantee that Trump will allow the memo to be released.

Read the full op-ed in the Washington Post.