Amid calls for House Intelligence Committee Chairman Adam Schiff, D-Calif., to resign, House Speaker Nancy Pelosi, D-Calif., ripped Republicans as "scaredy cats."

"I think they are just scaredy cats," Rep. Pelosi told reporters during her weekly briefing. "They just don't know what to do, so they have to make an attack. They did the wrong thing, the American people know that.

"It's their own insecurity, their own fear of the truth, their fear of the facts."

President Donald Trump has led the chorus against Rep. Schiff, who has long been a vocal critic of the president and is leading investigations into the administration and the Trump campaign on the back of special counsel Robert Mueller's investigation.

"They're just plain afraid," Pelosi continued. "They're afraid of the truth, they're afraid of competence, they're afraid of a leader who is recognized in our country for being calm, professional and patriotic."

The nine Republican members of the Schiff-led House Intelligence Committee signed a letter accusing the Democratic leader of being "at the center of a well-orchestrated media campaign claiming, among other things, the Trump campaign colluded with the Russian government."

Attorney General William Barr has summarized Mueller's report with a four-page letter Sunday, concluding there is no criminal conspiracy nor obstruction of justice on behalf of President Trump, despite Schiff's continued claims to the contrary.

The Mueller investigation was looking into Russia's attempts to sow discord in the U.S. democracy, something Schiff's ongoing claims actually are doing, the GOP argues.

"Your willingness to continue to promote a demonstrably false narrative is alarming," the GOP letter read by Rep. Mike Conaway, R-Texas, claimed. "The findings of the special counsel conclusively refute your past and present assertions and have exposed you as having abused your position to knowingly promote false information, having damaged the integrity of this committee, and undermined faith in U.S. government institutions."