People walk on Red Square past the Kremlin in December. (Yuri Kadobnov/AFP/Getty Images)

Top Democrats on Tuesday called on Facebook and Twitter to investigate what lawmakers said are Russian efforts to promote the release of a classified Republican memo criticizing the FBI probe of Russia’s meddling in the 2016 campaign.

Hashtags such as “#ReleaseTheMemo” have been trending on Twitter in recent days, and accounts affiliated with Russian influence efforts have been supporting this campaign, according to the Alliance for Securing Democracy, a U.S.-based group that examines efforts by Russia and other nations to interfere in democratic institutions.

“If these reports are accurate, we are witnessing an ongoing attack by the Russian government through Kremlin-linked social media actors directly acting to intervene and influence our democratic process,” said a letter to Facebook and Twitter from Rep. Adam B. Schiff and Sen. Dianne Feinstein, both Democrats from California who are the top members of their party on the House Intelligence Committee and Senate Judiciary Committee, respectively.

Efforts to disclose the classified memo, prepared by Republican congressional staffers, have in recent days moved to the center of a sharply partisan debate over the actions of investigators probing President Trump, his campaign and his associates. Some conservative lawmakers and prominent media personalities are pushing for the memo to be declassified and published to illuminate what they say have been improper actions by the FBI and Justice Department officials.

White House press secretary Sarah Huckabee Sanders said on Jan. 23 that the White House "supports full transparency" on a surveillance memo the House GOP is seeking to release. (Reuters)

At the center of these allegations are claims that investigators erred in conducting electronic surveillance in 2016 based on what critics contend was faulty information provided by British former spy Christopher Steele. He was the author of the now-famous Steele dossier, which used anonymous sources to sketch a broad portrait of financial and personal ties between Russians and the Trump campaign.

The dossier, whose contents Steele brought to the attention of the FBI in 2016, was among the early sources of allegations that triggered the probe now led by special counsel Robert S. Mueller III.

People who have read the classified memo say it seeks to discredit the Steele dossier’s allegations and suggests that Steele lied to the FBI. The memo also alleges that agents later used flawed information provided by Steele to secure a court order to conduct electronic surveillance on Trump campaign adviser Carter Page.

Steele has not publicly commented on the allegations reportedly contained in the memo.

FBI spokesman Andrew Ames said the bureau “has requested to receive a copy of the memo in order to evaluate the information and take appropriate steps if necessary. To date, the request has been declined.”

A Justice Department spokesman declined to comment.

Leaders of the House Freedom Caucus have sought to enlist Trump’s help in their bid to win public release of the memo. During a phone call Thursday, Rep. Mark Meadows (R-N.C.), the caucus’s chairman, and Rep. Jim Jordan (R-Ohio), a co-founder of the group, told Trump of the memo and their campaign to release it, according to people familiar with the call.

Rep. Mark Meadows (R-N.C.), left, and Rep. Jim Jordan, (R-Ohio), speak to the media on Capitol Hill last week. (Zach Gibson/Bloomberg)

A White House official acknowledged the call with the Freedom Caucus but said the president did not endorse the lawmakers’ plan to release the memo. But caucus members, once apprised by Meadows and Jordan of the conversation, were left with the opposite impression.

“It’s pretty clear that since it is so favorable to President Trump that he would want it released,” said caucus member Rep. Mo Brooks (R-Ala.). “I think it’s fair to infer with about a 99 percent probability that since it helps the president so much, that he would be happy if the public knows about it.”

Democrats, however, have dismissed the Republican campaign to publish the memo as a bid to undermine a legitimate law enforcement investigation into Trump’s campaign and transition. Democrats also have said that releasing information in the memo would amount to a break from past practice in the handling of classified material.

During the Thursday phone call, Trump was not initially familiar with the memo, according to the people familiar with the conversation. Trump also did not offer to back Freedom Caucus members seeking to force a vote releasing the document as a condition for supporting a short-term funding bill to head off the federal government’s looming shutdown, those people said.

Trump told the Freedom Caucus members that he needed a clean deal on government funding, according to a person familiar with the conversation who, like others, spoke on the condition of anonymity to discuss private deliberations. A vote on releasing the memo did not materialize last week, and the federal government shut down over the weekend before resuming operations Monday.

By Thursday evening, conservative Republicans had begun to tweet using the hashtag #ReleaseThe Memo.

A spokesman for House Speaker Paul D. Ryan (R-Wis.) confirmed that Trump plans to declassify the memo if the House agrees to release it. Ryan has been deferring to Intelligence Committee chairman Devin Nunes (R-Calif.) on how to proceed.

Trump’s son Donald Trump Jr. picked up on lawmakers’ campaign Friday morning, retweeting lawmakers , Fox News host Sean Hannity and others, and hitting the airwaves himself to promote the effort.

In alleging involvement by Russian trolls and bots, Schiff and Feinstein cite the Alliance for Securing Democracy, part of the German Marshall Fund. The group hosts on its website a dashboard that tracks roughly 600 accounts that the group says echo or otherwise support Russian influence efforts, though in some cases this is done unwittingly, according to information posted on the site.

It adds that many of the accounts are not directly controlled by Russia but amplify key themes put forth by Russian government media. The dashboard, called “Hamilton 68: Tracking Russian Influence Operations on Twitter,” shows #ReleaseTheMemo as the most commonly used hashtag by tracked accounts over the past 48 hours.

Facebook confirmed that it had received the letter from Schiff and Feinstein but did not immediately make further comment. Twitter issued a statement saying the company “is committed to addressing malicious activity on our platform, and we take any assertions of such activity very seriously. We look forward to working closely with Senator Feinstein and Congressman Schiff to address their questions.”

Clint Watts, a fellow at the Foreign Policy Research Institute and creator of the Hamilton 68 dashboard, said it was never intended to be a representative sample of tweets. Watts said the research does not claim that the hashtag was created by Russian operatives, but that Russian operatives amplified its messages. In the case of #ReleasetheMemo, Watts said Russian agents would be interested in the Twitter campaign because it discredits a U.S. institution.

Jonathon Morgan, founder of the nonprofit Data for Democracy, who also helped develop the dashboard, said that his group found a surge of about 400 new Russian bot accounts that were created in January. Another set of accounts tweeting the hashtag was created in 2009.

“It was as if somebody flipped the switch — as if someone copied the same message, the same hashtag, and we were tweeting about the same events, all at the same time,” Morgan said. “The key takeaway is these accounts were created just in January. So the idea that Twitter is on top of its bot problem, well, I think they are failing.”

The Alliance for Securing Democracy tracking tool does not attempt to measure how much of the social media conversation about the memo comes from accounts related to Russia. Such a project would require analysis of a broad, representative sample of tweets on the subject, along with information on who produced or shared such tweets — a process that typically takes weeks or months of work.

In seeking help from Twitter and Facebook on Tuesday, Schiff and Feinstein reminded the companies of their inability to stop Russian disinformation during the 2016 presidential campaign. Both companies have since acknowledged that the Internet Research Agency, in St. Petersburg, Russia, used their social media platforms to spread divisive messages during the election and its aftermath.

The Democratic lawmakers demanded a report by Friday and urged the companies to shut down any participating accounts found in violation of company policies.

“This should be disconcerting to all Americans, but especially your companies as, once again, it appears the vast majority of their efforts are concentrated on your platforms,” Schiff and Feinstein wrote. “This latest example of Russian interference is in keeping with Moscow’s concerted, covert, and continuing campaign to manipulate American public opinion and erode trust in our law enforcement and intelligence institutions.”

The urgent request for investigation underscores growing scrutiny on Capitol Hill of the influence of social media on American politics, as well as growing concern over release of the classified GOP memo. The letter is addressed to Facebook chief executive Mark Zuckerberg and Twitter chief executive Jack Dorsey.

The letter cites no evidence of Russian influence efforts on Facebook, but investigations of Russian manipulation of social media during the 2016 campaign found widespread exploitation of U.S.-based social media platforms. Researchers have a more difficult time tracking the flow of information on Facebook than Twitter, whose posts are more widely available to the public than on Facebook.

Ellen Nakashima, Mike DeBonis, Elizabeth Dwoskin, Tom Hamburger, Matt Zapotosky and Devlin Barrett contributed to this report.