WASHINGTON — President Donald Trump is prepared to approve the release of a controversial Republican-drafted memo about secret government surveillance as soon as today, a step that would put him at odds with his top national security officials but could give him a new tool to undermine public confidence in the Russia investigation.

The White House might not seek any changes to the classified document, a senior administration official said Thursday, even though FBI Director Christopher Wray and Director of National Intelligence Dan Coats have expressed concern about its contents.

“The president is OK with it,” the official said. “I doubt there will be any redactions. It’s in Congress’ hands after that.”

The FBI publicly warned Wednesday that it had “grave concerns” about the memo’s accuracy. Coats has privately expressed similar concerns to the White House, saying the release could set a troubling precedent for revealing classified information, according to another U.S. official.

Releasing the memo could put pressure on Wray, who was handpicked by Trump last spring to head the FBI, to respond or even step down. Trump fired Wray’s predecessor, James Comey, and has publicly berated several other senior officials at the bureau and the Justice Department, including Attorney General Jeff Sessions.

Comey tweeted Thursday night, “All should appreciate the FBI speaking up. I wish more of our leaders would. But take heart: American history shows that, in the long run, weasels and liars never hold the field, so long as good people stand up. Not a lot of schools or streets named for Joe McCarthy.”

The classified memo was prepared by aides to Rep. Devin Nunes, chairman of the House intelligence committee, which has been investigating Russia’s meddling in the 2016 election.

Nunes, R-Calif., has separately scrutinized claims of FBI surveillance abuses during the 2016 campaign. The document apparently cites selective information from FBI interviews with confidential informants, classified material provided to the Foreign Intelligence Surveillance Court, which meets in secret and must approve intelligence-related eavesdropping on U.S. citizens, and other highly sensitive material.

The memo reportedly claims that the decision to start surveillance of Carter Page, then a Trump campaign adviser with business interests in Russia, was based in part on information provided by Christopher Steele, a former British spy who was working for a U.S. firm collecting opposition research on Trump.

The subsequent counterintelligence collection on Page formed part of the broader criminal investigation, now led by special counsel Robert Mueller, into possible ties between the Trump campaign and Russian meddling in the election.

Republicans say the memo proves the FBI abused the Foreign Intelligence Surveillance Act process to undermine Trump’s campaign and ultimately his presidency.

Democrats on the committee say the cherry-picking of information from the FISA application shows Republicans deliberately sought to embarrass the FBI and discredit the Mueller probe.

The Republican majority on the committee agreed Monday to release the memo — but refused to allow the simultaneous release of a rebuttal document drafted by Democrats, widening the partisan clash.

Conservative commentators and lawmakers have amplified dark speculation that its contents are scandalous.

Democrats who have read the document say it skews the facts to present a partisan indictment.

“This memo is part of the slow-motion purge designed to undermine Robert Mueller’s investigation into the president and his allies,” said Michael Waldman, a former speechwriter for President Bill Clinton and president of the Brennan Center for Justice at New York University School of Law. “It’s yet another step on a slide into abuse of power.”

The conflict has divided Republican lawmakers, who were attending a retreat at a resort in White Sulphur Springs, W.Va., on Thursday and found themselves facing repeated questions about a classified memo many had not read, instead of their recent success pushing tax cuts through Congress.

Senate Republicans, who have not been allowed to review the House memo, appeared more hesitant than their House colleagues about bucking the FBI to stand by Trump.

Sen. John Thune of South Dakota, the third-ranking Republican in the Senate, said administration officials and members of Congress should heed law enforcement warnings and concerns about the memo. “They need to pay careful attention to what our folks who protect us have to say about how this bears on our national security,” he said.

House Republicans, on the other hand, were eager to publicize the memo. Rep. Mark Meadows, R-N.C., chairman of the conservative House Freedom Caucus, said he had “zero” concern about the FBI’s objections.

Lawmakers acknowledge the furor is being fueled in part by an influence campaign, including on social media, that is almost certainly being stirred up by Russian-aligned players, including Twitter bots. “The Russians aren’t causing that, but I have no doubt they’re engaging and trying to elevate it,” said Sen. James Lankford, R-Okla., a member of the Senate intelligence committee. “They’re the kid on the playground shouting, ‘Fight, fight, fight.’?”

brian.bennett@latimes.com