WASHINGTON (TNS) — The impending release of a classified memo about FBI surveillance of a former Trump adviser is further dividing Republicans, who now find themselves in the unusual position of bucking the nation's top law enforcement agency to stand by President Donald Trump in what could prove to be a risky political gambit.

Critics say the memo is a blatant attempt to discredit the probe into possible collusion between the Trump campaign and Russia, and whether the president tried to hinder the investigation.

Republican leaders insist it is an important exercise of congressional oversight to ensure the FBI and Justice Department do not overstep their bounds by improperly spying on Americans.

"What this memo is, is Congress doing its job and conducting oversight," House Speaker Paul D. Ryan, R-Wis., told reporters covering a GOP retreat at the Greenbrier Resort in West Virginia.

Even so, many top Republicans have expressed unease with making public the GOP memo, drafted by House Intelligence Committee Chairman Devin Nunes, R-Calif., one of Trump's most loyal supporters on Capitol Hill.

In supporting the memo's release, Ryan and Senate Majority Leader Mitch McConnell, R-Ky., now find themselves at odds with the FBI, which warned of "grave concern" over inaccuracies and misrepresentations. The memo focuses on the FBI's surveillance of Trump's former adviser Carter Page and his repeated contacts with Russians. The White House has repeatedly tried to distance itself from Page, who left the campaign months before the election.

Sen. John Thune of South Dakota, the chamber's third-ranking Republican, admonished the administration and members of Congress to heed the warnings of the FBI.

"There are important national security considerations they need to weigh," Thune told reporters.

"I think they have to take into consideration what the FBI is saying. ... They need to pay careful attention to what our folks who protect us have to say about how this bears on our national security."

At minimum, Thune said, the memo should be reviewed by the Senate Intelligence Committee before becoming public. The Senate Intelligence Committee asked to see the memo last week but was denied, said an aide to the chairman, Sen. Richard Burr, R-N.C.

The situation represents yet another split from Republican norms as the GOP — which traditionally puts national security above other concerns, including privacy — adjusts its priorities in the age of Trump.

Ryan on Thursday tried to downplay any confrontation with the FBI, insisting he was chiefly concerned about safeguarding "Americans' civil liberties."

Ryan said the memo was not intended to discredit FBI Director Christopher A. Wray and Deputy Attorney General Rod Rosenstein, who oppose its release, or special counsel Robert S. Mueller III, who is heading the Russia investigation.

Instead, he sought to frame the chairman's work on the memo as an effort shine light on potential wrongdoing at the FBI.

"The vast, vast majority of the men and women of the FBI are doing a great job. ... But we also have to make sure that if there are certain individuals who did the wrong thing — who either brought bias or cut corners or did something wrong that implicates Americans' civil liberties — then it is our job as Congress overseers to bring people to account so it doesn't happen again," Ryan said.

He dismissed calls from House Minority Leader Nancy Pelosi, D-Calif., and Senate Minority Leader Charles E. Schumer, D-N.Y., to remove Nunes from the panel.

By releasing the memo, Trump, who has tried to push the investigation of Russian influence in the 2016 election out of the spotlight, now risks keeping the probe at the forefront of debate.

House Republicans are increasingly steadfast in their push to publicize the report, and Ryan has allowed Nunes wide authority to pursue the release despite the FBI's objections.

Rep. Mark Meadows, R-N.C., chairman of the conservative House Freedom Caucus, said he had "zero" concerns about the FBI's objections and hoped the memo could be made public as soon as possible.

"I'd like to see it out today," said Meadows, who helped broker the release of the memo as part of the deal to fund the government ahead of the shutdown.

Other top Republicans, including Rep. Mac Thornberry, R-Texas, the chairman of the Armed Services Committee, also said the report should be made public.

Thornberry said neither Defense Secretary James N. Mattis nor Secretary of State Rex Tillerson addressed the memo or raised concerns about it during a morning session at the retreat. "It should be released," Thornberry said.

Lawmakers acknowledged that the debate over the memo is being fueled in part by an influence campaign, including on social media, that was almost certainly being stirred up by Russian-aligned players.

"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 Intelligence Committee. "They're the kid on the playground shouting, 'Fight, fight, fight.'"

Democrats have called the memo an attempt to discredit the investigation into possible collusion between Trump's campaign and Russia.

"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," Pelosi said in a statement. "Congressman Nunes' deliberately dishonest actions make him unfit to serve as chairman, and he must be removed immediately from this position."

The top Democrat on the Intelligence Committee, Rep. Adam Schiff of California, said the memo approved by the panel's Republicans was changed by Nunes before being submitted to the Trump administration for review.

But Ryan said the committee simply undertook the proper changes to "scrub" sensitive material before turning the report over to the White House.