House Intelligence Committee Chairman Devin Nunes, R-Calif., speaks to reporters on Capitol Hill in Washington, Friday, March 24, 2017. AP Photo/J. Scott Applewhite The chair of the House Intelligence Committee threatened to hold the attorney general and FBI director in contempt of Congress.

The dispute lays bare the tension amid the committee's Russia investigation.

The ranking Democrat on the committee said it appeared the chair was attempting to "put the government on trial."

The chairman of the House Intelligence Community threatened to hold Attorney General Jeff Sessions and FBI Director Chris Wray in contempt of Congress if they did not respond to a subpoena for documents or testimony relating to the dossier alleging President Donald Trump's ties with Russian officials.

In a letter dated September 1 and obtained by CNN, Rep. Devin Nunes vented about the pair's "insufficient responsiveness to the committee's numerous Russia-investigation related requests over the past several months."

It is unclear whether Nunes — whose signature was the only one to appear on the letter and who, as chairman, has the power to sign off on subpoenas — was acting on behalf of committee Republicans when he subpoenaed "any and all documents relating to the agencies' relationship with former British Secret Intelligence Service officer Christopher Steele and/or the so-called 'Trump dossier'" on August 24.

Nunes' subpoenas, to which the DOJ and FBI apparently did not respond by the September 1 deadline, also covered documents "memorializing FBI's relationship with Mr. Steele, any payments made to Mr. Steele, and efforts to corroborate information provided by Mr. Steele and his sub-sources — whether directly or via Fusion GPS."

Fusion GPS, an opposition research firm, hired Steele in late 2015 to dig up dirt on then-candidate Trump on behalf of anti-Trump Republicans. Democrats took over funding for the research after Trump won the Republican nomination.

Rep. Adam Schiff, the committee's ranking Democratic member, told MSNBC on Tuesday night that he was "perplexed" when the committee's majority — likely represented by Nunes — told Democrats during the summer recess that they wanted to issue the subpoenas.

"We don't subpoena parties unless they turn down our requests for information, which the DOJ and the FBI really hadn't done," Schiff said. "So we opposed it. We thought it wasn't warranted. They told us they were going to do it anyway."

Schiff said Democrats have been wanting to subpoena the White House for documents related to the firing of former FBI Director James Comey, but the Republicans on the committee "have not been willing." He also claimed that Republicans were trying to "antagonize the FBI and the DOJ, and trying to provoke a conflict" with special counsel Robert Mueller, who is investigating Russia's election interference.

(L to R) House Intelligence Committee Chairman Devin Nunes (R-CA) and ranking member Rep. Adam Schiff (D-CA). Mark Wilson/Getty Images

Democratic Rep. Mike Quigley, a member of the House Intelligence Committee, echoed Schiff's claim that the majority had operated outside of "standard practice" when it issued the subpoenas.

"Unfortunately, this decision by the majority stands in stark contrast to how they've treated other evidence in this investigation by first requesting voluntary compliance instead of jumping straight to subpoenas," Quigley said in a statement provided to Business Insider.

"The sole purpose of this subpoena is to discredit Christopher Steele instead of doing our due diligence to evaluate whether the claims in his report are true," he said.

'Trying to put the government on trial'

Nunes' subpoenas also directed the DOJ and the FBI to "provide copies of any Foreign Intelligence Surveillance Act (FISA) applications submitted to the Foreign Intelligence Surveillance Court (FISC) — whether or not approved by the FISC — incorporating information provided by Mr. Steele, his sub-sources, and/or Fusion GPS," according to the letter.

CNN reported in April that the FBI used the explosive, unverified dossier detailing Trump's alleged ties to Russia to bolster its case for a warrant that would allow it to surveil Carter Page, an early foreign-policy adviser to Trump's campaign.

Experts have explained that the FBI's use of the dossier to bolster the warrant means the bureau had enough confidence in the validity of the document to work to corroborate it and present it in court.

"In my long experience in dealing with FISA processing, unconfirmed information about a potential target cannot (and has not been) included in the application‎," John Rizzo, the former acting general counsel of the CIA, said in an interview earlier this year.

"So, if the CNN report is accurate, then I have to believe that the FBI and Department of Justice concluded (and the Court agreed) that the info in the dossier about Page was reliable," Rizzo said, "and in all likelihood was backed up by other available intelligence."

Nunes now wants to know why the FBI and the DOJ reportedly thought the information in the dossier was worth pursuing — and he has threatened to hold Sessions and Wray in contempt of Congress if they fail to provide "the documents in full or testimony" in an open hearing on September 14 "to explain under oath" their "unwillingness or inability to comply in full with the subpoenas."

Republican Rep. Mike Conaway took over the committee's Russia probe after Nunes stepped aside from the investigation in early April following his decision to brief Trump and the press on classified intelligence — without telling his fellow committee members.

Nunes said the intelligence showed Trump and his transition team had been "incidentally" surveilled after the election, but Schiff said at the time that he saw nothing that warranted Nunes' decision to go around his colleagues.

Conaway told reporters on Wednesday that he supported obtaining all of the relevant documents related to the dossier: "We've got to run this thing to ground," he said.

Schiff, meanwhile, suggested he thinks something more sinister is happening.

"I think what's going on here is something I saw back in my days of a prosecutor," Schiff told MSNBC. "Sometimes the defense opts for a strategy of trying to put the government on trial. And here I think there's a hope that if they can impeach Christopher Steele, and if they can impeach the FBI and DOJ, then maybe they can impeach the whole Russia investigation."