Congressional Democrats have requested an FBI briefing for all members of Congress regarding foreign efforts to interfere in the 2020 presidential election by spreading disinformation in order to influence lawmakers, according to a letter released Monday.

“We are gravely concerned, in particular, that Congress appears to be the target of a concerted foreign interference campaign, which seeks to launder and amplify disinformation in order to influence congressional activity, public debate, and the presidential election in November,” the Democrats wrote to Wray last Monday.

Democrats Nancy Pelosi, Adam Schiff, Mark Warner and Chuck Schumer, the authors of the letter, did not specify which foreign governments are allegedly involved in the disinformation efforts, or which lawmakers are being targeted in the scheme.

Some Democratic lawmakers have asserted that the Russian government is behind a disinformation campaign regarding former Vice President Joe Biden and his son Hunter’s activities in Ukraine.

Republican Wisconsin Sen. Ron Johnson, the chairman of the Senate Homeland Security Committee, is leading an investigation into Hunter Biden’s work with Burisma, the Ukrainian energy company.

Democratic Sens. Gary Peters and Ron Wyden sent a letter to Johnson last Thursday requesting a briefing about the Burisma-Biden probe, saying they wanted to understand the “counterintelligence implications of foreign election interference and your ongoing investigative work.”

Schiff, the chairman of the House Intelligence Committee, may himself have spread Kremlin disinformation related to President Donald Trump and members of his campaign.

Schiff has repeatedly touted the infamous Steele dossier, which alleged that Trump campaign advisers conspired with Russia to influence the 2016 election.

In a March 20, 2017 hearing, Schiff read several of the dossier’s allegations into the public record. He has also cited the document in interviews to call for additional investigation into the Trump campaign.

But the dossier, written by former British spy Christopher Steele, may itself contain Russian disinformation.

A Justice Department inspector general’s report said that the FBI had evidence that Russian intelligence operatives may have fed disinformation to Steele through his network of sources.

The FBI relied heavily on Steele’s information in its investigation into the Trump campaign.