House Intelligence Committee Chairman Adam Schiff, a Democrat, and GOP ranking member Devin Nunes came together in a rare bout of bipartisanship to demand "full visibility" into the findings of special counsel Robert Mueller, citing the probe's counterintelligence origins and the committee's own statutory oversight responsibilities.

In a letter dated March 27 and addressed to Attorney General William Barr, his deputy Rod Rosenstein, and FBI Director Chris Wray, the committee leaders asked to be provided with "all materials, regardless of form and classification, obtained or produced by the Special Counsel's Office in the course of the investigation."

Schiff and Nunes said those materials should include records related to the investigation's scope and subjects as well as any "raw reporting" related to intelligence or counterintelligence matters. They also requested a briefing for the full committee from Mueller himself, alongside members of his senior team and relevant law enforcement and national security officials. The letter was obtained by CBS News from a congressional source.

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The Justice Department announced Monday that it would publicly release a redacted version of Mueller's completed report on Thursday of this week, but several congressional leaders have demanded access to much more. The House Judiciary committee, chaired by Democrat Jerry Nadler, threatened to subpoena an unredacted version of the report and its underlying investigative documents earlier this month.

"The Constitution charges Congress with holding the president accountable for alleged official misconduct," Nadler said in an April 3 statement. "That job requires us to evaluate the evidence for ourselves — not the attorney general's summary, not a substantially redacted synopsis, but the full report and the underlying evidence."

In their letter, Schiff and Nunes — who have seldom seen eye to eye since the launch of a number of investigations into the 2016 election — cite the committee's "independent constitutional duty and express statutory right" to examine information gathered by the special counsel in order to "assess the counterintelligence and national security implications, and formulate appropriate remedies in response."

Nunes appears to have signed the letter one day before he and the other Republicans on the committee demanded Schiff's resignation, accusing the chairman of "undermining" the panel's credibility by implying the Trump campaign colluded with the Russian government. Schiff has maintained that evidence is abundant but accepts the special counsel's finding that it did not rise to the level of a criminal charge. Before they won the majority in 2018, Democrats on the committee had demanded Nunes' resign the chairman's post due to his perceived connections to the White House.

The House and Senate Intelligence committees, both established in the late 1970s, are charged with overseeing the numerous departments and agencies that make up the U.S. intelligence community, and are entitled by law to certain materials, including sensitive or classified information, as part their oversight mandate.

A spokeswoman for Senate Intelligence Committee Chairman Richard Burr, a Republican, declined to comment on whether that committee has made a similar request. Burr has previously told reporters he expected the "Gang of Eight," a select, bipartisan group of lawmakers who are briefed on classified matters, to receive "some type of briefing."