In the most significant escalation yet in the wrangling between Congress and the FBI over the Trump dossier, the House Intelligence Committee has subpoenaed the bureau and the Justice Department for documents relating to the dossier, the FBI's relationship with dossier author Christopher Steele, and the bureau's possible role in supporting what began as an opposition research project against candidate Donald Trump in the final months of last year's presidential campaign.

The subpoenas are an indication of growing frustration inside the committee over the FBI and Justice Department's lack of cooperation in the Trump-Russia investigation.

The committee issued the subpoenas -- one to the FBI, an identical one to the Justice Department -- on August 24, giving both until last Friday, September 1, to turn over the information.

Neither FBI nor Justice turned over the documents, and now the committee has given them an extension until September 14 to comply.

Illustrating the seriousness with which investigators view the situation, late Tuesday the committee issued two more subpoenas, specifically to FBI Director Christopher Wray and Attorney General Jeff Sessions, directing them to appear before the committee to explain why they have not provided the subpoenaed information.

The subpoenas are the result of a months-long process of committee investigators requesting information from the FBI and Justice Department. Beginning in May, the committee sent multiple letters to the FBI and Justice requesting information concerning the Trump-Russia affair.

"We got nothing," said committee member Rep. Trey Gowdy, R-S.C., who is taking a leading role in the Russia investigation. "The witnesses have not been produced and the documents have not been produced."

In a telephone interview Tuesday, Gowdy said the FBI has said it needed more time to comply, and also that complying might interfere with the investigation of special counsel Robert Mueller. Whatever the reason, the documents haven't been produced.

"A subpoena is a tool of last resort in Congress," Gowdy, a former federal prosecutor, said.

Like investigators with the Senate Judiciary Committee, who are also pursuing information about the dossier, the House committee wants to know the origin of the FBI's involvement in the creation of the document. They are particularly interested to know whether the FBI or Justice Department ever presented information from the dossier -- unverified, possibly from paid informants -- to a court as a basis for obtaining a surveillance warrant in the Russia investigation.

"I want to know the extent to which it was relied upon, if at all, by any of our intelligence agencies or federal law enforcement agencies," Gowdy said, "and to the extent it was relied upon, how did they vet, or either corroborate or contradict, the information in it?"

The House intelligence panel, like the Senate Judiciary Committee, has had so-called "de-confliction" discussions with Mueller's office and believes the special counsel does not object to the House seeking information on the dossier.

The committee believes that seeking information on the origin of the FBI's role in the dossier, and the bureau's relationship with dossier compiler Steele, a former British spy, will lead to a better understanding of the FBI's entire counter-intelligence probe on the question of Russian interference in the 2016 campaign.

"Several of our lines of questions centered on the dossier, or, if you don't like the word 'dossier,' just insert 'the origin of the Russia investigation,'" said Gowdy.

Gowdy and other House Republicans are struck by the fact that a standoff has developed between a GOP-controlled House and a GOP-controlled Justice Department. "I'm sure you're noting with the same irony I'm noting the difficulty that a Republican Congress is having getting information from a Department of Justice run by Jeff Sessions," Gowdy said.

Nevertheless, the committee seems determined to prevail. "Congress created the FBI, we created the Department of Justice, we're the ones who passed the laws that set the boundaries of their jurisdiction, and and we're the ones that fund them," Gowdy noted. "It is not illegitimate for us to ask what prompted this investigation, and it is certainly not illegitimate for us to test and probe the reliability of that underlying information, particularly if, in theory, there are either charging decisions and/or court filings that relied upon that information."