The National Security Agency is “moving forward” to install Michael Ellis, a former GOP political operative and White House official, as the agency’s top lawyer, the agency said Sunday.

The announcement came a day after acting defense secretary Christopher C. Miller ordered the NSA director, Gen. Paul Nakasone, to immediately place Ellis in position as the agency’s general counsel.

Ellis had been selected for the job in November by the Pentagon general counsel after a civil service competition. But Nakasone was not in favor of Ellis’s selection and sought to delay his installation, according to several people familiar with the issue, who, like others, spoke on the condition of anonymity because of the matter’s sensitivity.

Ellis probably will start work Tuesday, the day before the Biden administration takes office, several people said.

Although Nakasone is not the hiring authority — the decision is made by the Pentagon general counsel — by tradition, the NSA director weighs in on the selection.

“Mr. Ellis accepted his final job offer yesterday afternoon,” the NSA said in a statement Sunday. “NSA is moving forward with his employment.”

In a statement, Pentagon public affairs officer Russell Goemaere said once a candidate is selected through the merit system, meets the job requirements and accepts an offer, if the person is not installed, “it exposes the department, agency and senior leadership to claims for a violation of the merit system principles and processes.” Congressional or media attention to a hiring decision are not justification “to delay placing a selected qualified individual in a position,” he said.

Ellis was selected under pressure from the White House, people familiar with the matter said at the time. The move drew criticism from national security legal experts as an attempt to politicize a career position.

Rejecting the charge of politicization, one U.S. official pointed out Saturday that the two previous NSA general counsels had ties to the Obama administration. Glenn Gerstell, who retired a year ago, raised $50,000 for the Obama campaign in 2012, he said. And Gerstell’s predecessor, Raj De, was White House staff secretary in the Obama administration before arriving at the NSA.

There also have been concerns about Ellis’s qualifications for the job, according to several people. One person said those issues included the possibility that he was chosen over candidates who scored higher during the interview process.

“This is a transparent effort to subvert civil service rules,” said Susan Hennessey, a former lawyer in the NSA’s Office of General Counsel who is a senior fellow in governance studies at the Brookings Institution. “No one could possibly defend this apparent hiring process as being free from impermissible political interference. If the NSA director has been given a direct order to install Ellis in this role, despite serious concerns regarding the legality of doing so, then he has no alternative.”

On Wednesday at noon, Hennessey said, a newly sworn-in President Biden will have a range of legal remedies to remove Ellis from the position — at least until outstanding legal and qualification questions are resolved.

Once Biden has in place a new general counsel, that person may be able to fire Ellis if, for instance, he or she determines that Ellis was installed in violation of the law or of policies preventing the embedding of political personnel into career civilian positions before a change in administration, Hennessey said. Ellis’s last post before moving to the NSA was White House senior director for intelligence, a political position.

Ellis could challenge that removal, but the burden would be his to demonstrate the process was regular, Hennessey said.

A new general counsel also would be able to reassign Ellis within the sprawling universe of civilian Defense Department agencies as long as it is to a position of equal rank in the defense intelligence senior executive service, she said.

The Biden team is reviewing its options for dealing with political appointees who are embedded or “burrowed” into career positions just before the new administration takes over, said a person familiar with the matter.

Concerns with Ellis are linked to his relationship with Rep. Devin Nunes (R-Calif.), a Trump loyalist. Ellis served as chief counsel to Nunes when Nunes chaired the House Intelligence Committee.

Ellis also was caught up in the controversy surrounding the prepublication review of former national security adviser John Bolton’s book for classified information. According to Ellen Knight, a former career White House official in charge of the review, Ellis tried to prevent the release of a portion of the manuscript that dealt with Ukraine and that presumably would be damaging to President Trump were it to come out during his 2020 impeachment trial in the Senate.

Ellis also conducted his own review of the manuscript and, as a political appointee, countermanded the career officials’ conclusion that the book was cleared for publication, according to Knight, who documented her concerns in a September 2020 letter.

Some critics have raised fears that Ellis might seek to exploit access to classified intelligence for political reasons. But the NSA general counsel, former officials noted, does not have the authority to classify or declassify intelligence.

A more fundamental concern, Hennessey said, is that Ellis, who was installed despite Nakasone’s reservations, apparently does not enjoy the NSA director’s confidence.

“That is not an individual who can credibly lead the general counsel’s office,” she said. “That provides a separate basis to remove Ellis in the future.”

Ellis joined the White House in 2017, when he became a lawyer on the National Security Council, and in 2019, he was elevated to senior director. He held that position as recently as earlier this month. It is not clear when he served his last day.

Anne Gearan contributed to this report.