A spate of personnel changes atop the intelligence community, currently led by acting Director of National Intelligence Richard Grenell, has prompted the leadership of the congressional intelligence committees to send letters of warning and a request that high-level staff changes within the intelligence community cease until a permanent director is in place.

On Tuesday, House Intelligence Committee Chairman Adam Schiff wrote a four-page letter to Grenell expressing "concern" about recent changes made to the Office of the Director of National Intelligence's (ODNI) leadership ranks and organization, which Schiff said took place without consultation with or authorization from Congress.

"Congress has neither authorized organizational changes at ODNI, nor appropriated funds for that purpose," Schiff wrote. "The committee is concerned, moreover, by the removal or departure of every Senate-confirmed official at ODNI, as well as of other senior officials across ODNI's leadership team, including [National Counterterrorism Center] Acting Director Russell Travers and Acting Deputy Director Peter Hall."

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The committee's Ranking Member, Republican Devin Nunes of California, did not co-sign the correspondence from Mr. Schiff, though he was copied on the letter.

A Senate Intelligence Committee aide confirmed that both of its leaders — Chairman Richard Burr of North Carolina and Vice Chairman Mark Warner of Virginia — recently sent a joint letter to Grenell insisting that Congress be consulted about potential changes to both structure and leadership at ODNI and that personnel changes be put on hold until a director is confirmed. Their letter, whose text included committee-sensitive information and has not been publicly released, received perfunctory acknowledgement from Mr. Grenell, according to the aide. The existence of the Senate committee's letter was first reported by a columnist for the Washington Post.

Mr. Schiff's letter on Tuesday included a similar admonition. "President Trump did not nominate you for confirmation as permanent DNI," he wrote to Grenell, "and it would be inappropriate for you to pursue any additional leadership, organizational or staffing changes to ODNI during your temporary tenure."

He requested a written explanation from Grenell for the changes made to date at ODNI by April 16.

In February, after nominating Grenell as acting DNI, President Trump then re-nominated Republican congressman John Ratcliffe of Texas to serve in the role on a permanent basis. It is unclear when Ratcliffe's confirmation process might be initiated. He withdrew his initial nomination in August after questions arose about his national security experience.

Travers and Hall, who had led National Counterterrorism Center (NCTC), were abruptly replaced last month by career intelligence officials who will lead the center in an acting capacity until Christopher Miller, Mr. Trump's official nominee for director, is confirmed by the Senate.

Their removal prompted a public outcry from former senior intelligence officials, including Joseph Maguire, Grenell's immediate predecessor, who wrote in an op-ed in The Washington Post that the officials' "unceremonious removal" sent a "damaging message" to members of the intelligence community.

In his letter, Schiff also raised the recent ouster of the Intelligence Community Inspector General (IC IG), Michael Atkinson, by Mr. Trump, who said he "no longer" had confidence in Atkinson. A career government official, Atkinson had deemed the whistleblower complaint that led to Mr. Trump's impeachment "credible."

"Mr. Atkinson acted with the highest integrity and remarkable professionalism, even as he was falsely attacked by the President and his supporters in Congress for staying true to his oath," Schiff wrote. Schiff noted hat the committee would "review" the circumstances of Atkinson's firing. He asked Grenell to confirm in writing that the IC IG's ability to conduct investigations had not been and would not be curtailed.

Schiff's final request centered on election security and the March 10 congressional briefing delivered by administration officials. Sources familiar with that briefing told lawmakers they had "nothing to support" the notion that Russian President Vladimir Putin favored one presidential candidate or another or had ordered actions on any candidate's behalf.

Three sources familiar with both briefings said there were inconsistencies between the election security assessment delivered on March and the one given to the House Intelligence Committee in February. The earlier briefing was delivered by Shelby Pierson, who serves as the Intelligence Community Election Threats Executive. Bill Evanina, the acting director of the National Counterintelligence and Security Center at ODNI, represented the intelligence community at the March briefing.

"Reports indicate that one or more members of your staff may be inappropriately interfering with the production and briefing of intelligence information on election security to Congress, including information that was briefed to all Members on March 10," Schiff wrote. "[I]t calls into doubt whether Congress and the American people can trust that the IC will continue producing unvarnished intelligence assessments on foreign interference efforts as the 2020 presidential election approaches."

Schiff asked Grenell to hand over all correspondence related to the March briefing by April 16 and for a quarterly update on election security by the end of May.

Grenell tweeted on Tuesday in response to news reports about Schiff's letter. "His letter was sent to the press before it was sent to me. These press leaks politicizing the intelligence community must stop," Grenell wrote.

A House Intelligence Committee official said that the letter was sent to ODNI at 1:14 p.m., and that ODNI had confirmed receipt of it. The letter was provided to reporters at 1:28 p.m.

ODNI did not immediately respond to a request for comment. A spokesperson previously told CBS News that Grenell is overseeing an effort studied but not implemented by previous directors to "refocus or transfer activities at ODNI to eliminate duplication of work with other agencies."