Republicans in both the House and Senate are growing increasingly frustrated with the FBI and Justice Department over tight restrictions on classified and other confidential information in the Trump-Russia affair.

The restrictions mean the FBI and Justice Department control what congressional investigators may see; under what conditions they may see it; and what they may make public. The practical result is that voters remain in the dark about hugely consequential events going on in Washington.

Two recent events have served to heighten tensions: the investigation into the Trump dossier and the revelation of text messages between FBI officials Peter Strzok and Lisa Page. In both cases, the FBI, appearing to protect its own actions and prerogatives, has made congressional oversight an exercise in pulling teeth, and members of Congress are tired of it.

That frustration could be heard Wednesday in a speech from Sen. Chuck Grassley, R-Iowa, chairman of the Senate Judiciary Committee.

On Jan. 4, Grassley and Sen. Lindsey Graham, R-S.C., chairman of the crime and terrorism subcommittee, sent a criminal referral to the FBI and Justice Department concerning Christopher Steele, the former British spy who authored the Trump dossier. In a cover letter, Grassley and Graham suggested that Steele might have lied to the FBI during his association with the bureau as he compiled the dossier.

That's all the cover letter said. The referral itself, which was classified, made the actual case about Steele. Grassley wrote an unclassified version of the referral for public release — finally, the public could understand what the case was about — but first sent it to the FBI to make sure the information in the unclassified version was in fact unclassified.

That's when Grassley got the runaround. The FBI "falsely claimed" — Grassley's words — that a portion of the document was classified and thus held up release. The information was not classified, Grassley said — it was based on "non-government sources" and "the deputy attorney general has discussed the fact at issue with me more than once in an unsecure space and on an unsecure phone line."

"Unfortunately, I suspect something else is really going on here," Grassley said. "It sure looks like a bureaucratic game of hide the ball, rather than a genuine concern about national security."

Grassley and Graham's referral remains in FBI limbo — and the public remains in the dark about what it reveals.

Then there are the FBI texts. Bureau officials believe there are about 50,000 texts between Strzok and Page, both of whom were deeply involved with the Hillary Clinton email investigation and the Trump-Russia investigation. Since the first public disclosure of the texts in early December, the FBI has given Congress somewhere between 6,000 and 8,000 — a rough estimate — out of the total 50,000.

Beyond that, of course, the FBI just a few days ago informed Congress that thousands of texts covering a key period of the Trump probe — Dec. 14, 2016 to May 17, 2017 — are missing. The FBI claimed a technical glitch was to blame, and Attorney General Jeff Sessions has pledged to use all the department's technical resources to attempt to recover them. In any event, that's more information the FBI and Justice Department have either turned over in dribs and drabs, refused to hand over at all, or claimed does not exist.

In that Senate speech, Grassley also expressed frustration about FBI and Justice Department footdragging in the overall Trump-Russia investigation. The department has provided "very limited access" to classified information and "tried to severely limit" the congressional staff who can review documents. That has slowed work to a snail's pace.

Grassley also offered support for making the House Intelligence Committee "FISA abuse" memo public. Grassley noted that his Senate committee has "access to the same information" House Intel used in writing the memo, but does not have the same authority to release classified information that the House has.

"Based what I know, I agree that as much of this information should be made public as soon as possible, through the appropriate process," Grassley said of the House memo. "And, I don't just mean the summary memos. The government should release the underlying documents referenced in those memos, after deleting any national security information that truly needs to be protected. But most of this story can be told, and should be told. The American people deserve the truth."

The House Intelligence Committee will likely vote next week to make the memo public. As for the underlying documentation, it is possible committee Republicans will support making that public, too, especially after Democrats have claimed that the memo does not accurately present the information in the underlying intelligence.

Now, House Democrats say they will write a memo of their own, which they will also want to release.

Judging from their behavior so far, the FBI and Justice Department would be happy if none of the information were ever made public. But the issue is just too important — after all, many Democrats hope to use the Trump-Russia affair to remove the president from office — for the evidence to remain secret. Pressure is mounting to let the public see what the FBI, Justice Department, and congressional investigators already know.