Republicans insist the American people have a right to see its contents, which they have hinted shows misuse of government surveillance powers and misconduct in the FBI’s investigation of ties between the Trump campaign and Russia.
A push by Republicans to release the document, which was compiled under the auspices of the House Intelligence Committee's Republican majority, has divided the government and posed a dilemma for President Trump.
"The FBI was provided a limited opportunity to review this memo the day before the committee voted to release it. As expressed during our initial review, we have grave concerns about material omissions of fact that fundamentally impact the memo's accuracy," the FBI said in a rare public statement.
The House Intelligence Committee voted along party lines this week to release the memo. Mr Trump has until the weekend to decide whether to make it public.
Democrats on the House panel - who had an effort to release a counterpoint memo defending the FBI's conduct blocked by Republicans - have said the memo selectively uses highly classified materials in a misleading effort to discredit Special Counsel Robert Mueller, who is leading the Justice Department's Russia probe, and Deputy US Attorney General Rod Rosenstein, who hired him.
Assistant Attorney General Stephen Boyd wrote to Republicans last week to warn releasing the memo would be “extraordinarily reckless”. The FBI's director, Christopher Wray has also sought to discourage the president over its release because the memo contains inaccuracies, according to Bloomberg
The decision over whether to do so now falls to Mr Trump, who has frequently lambasted the Russia investigation as baseless and accused the FBI of failing to run an impartial probe. Mr Trump was picked up by broadcast microphones assuring a Republican legislator that he was “100 per cent” in favour of releasing the memo, in the wake of his State of the Union address on Tuesday night.
White House Chief of Staff John Kelly followed that up by telling Fox News Radio on Wednesday that the memo "will be released here pretty quick, I think, and then the whole world can see it.” He added that he had seen the four-page document and that White House lawyers were reviewing it. White House Press Secretary Sarah Sanders told CNN that “there's always a chance” that it would not be released.
Both the FBI and the Justice Department have tamped down allegations that they abused spying powers granted by the Foreign Intelligence Surveillance Act (FISA). Mr Boyd said officials were “unaware of any wrongdoing” in obtaining surveillance permission, and the FBI said it “takes seriously its obligations to the FISA Court and its compliance with procedures overseen by career professionals in the Department of Justice and the FBI”.
House Speaker Paul Ryan has claimed the memo shows “there may have been malfeasance at the FBI by certain individuals" and that “there are legitimate questions about whether an American's civil liberties were violated by the FISA process.” However, Mr Ryan said the memo should not be used to undermine Mr Mueller and his investigation into Russian meddling into the 2016 presidential election and possible connections into Mr Trump's campaign team and the Kremlin.
After Republicans voted to release the memo, the top Democrat on the intelligence committee Adam Schiff blasted “an effort to circle the wagons around the White House and distract from the Russia probe”. He followed that up with a tweet on Wednesday saying Republicans have “used this memo to mislead the House. Will the president now use it to mislead the country?”
More about: FBI