The Trump administration installed loyalists on a Pentagon advisory panel Friday, naming former campaign officials Corey Lewandowski and David Bossie among the new appointees to the Defense Business Board.

Acting defense secretary Christopher C. Miller, appointed to his job last month after the firing of Mark T. Esper, said in a statement that he was “proud” to welcome each of the new members and looked forward to their contributions to help guide the Defense Department’s business efforts in coming years.

“These individuals have a proven record of achievement within their respective fields and have demonstrated leadership that will serve our Department, and our nation well,” Miller said in a statement.

The appointments were announced along with the dismissal of other members, injecting partisanship into a board that is rarely discussed outside the Defense Department and defense industry. Lewandowski and Bossie worked together on the Trump presidential campaign in 2016 and later co-authored a memoir titled “Let Trump Be Trump.”

Michael Bayer, who was ousted as chairman of the board, said in a phone interview that he was informed of the administration’s decision to dismiss him with a form letter that was emailed to him on Friday morning. He said he does not know the politics of most of the board’s members and that they have typically operated in a nonpartisan manner.

“Frankly, I was surprised,” Bayer said. “I think it’s lamentable because I think the taxpayers spend an enormous amount of money on the department, and the overwhelming amount of what that department does involves business dollars.”

Bayer said there was room to add new members on the board without removing anyone else. By charter, the board has up to 25 members, and it has been expanded to include up to 35 in the past, he said. Before Friday, it had 16 members, according to its website.

Another member removed on Friday said that he was told that the defense secretary’s office was not informed of the administration’s decision before the firings. He questioned the acumen of some of the new appointees.

“It does not appear to me they have the business credentials and expertise that is normally required to serve on the business board,” he said, speaking on the condition of anonymity due to the sensitivity of the issue.

He predicted that the new members will not last, since they are “really political appointees.”

The board reports to the defense secretary, allowing the Biden administration to handle the appointees as it sees fit beginning in January. Their job is to provide unpaid independent advice and recommendations about the Pentagon’s “management, business processes and governance from a private sector perspective,” according to the board’s charter.

The dismissals, first reported by Politico, also include vice chairman Atul Vashistha and members Arnold Punaro, John O’Connor, David Venlet, Paul Dolan, Scott Dorn, David Walker and David Van Slyke. The Pentagon statement said they were “serving in expired positions” or that their “tenures were terminated” without explaining how the Trump administration came to make the decision to remove them now. Bayer said that at least some of the ousted members had nearly a year left on their terms.

The other new appointees include Henry Dreifus, Robert McMahon, Cory Mills, Bill Bruner, Christopher Shank, Joseph Schmidt, Keary Miller, Allen Weh and Earl Matthews.

But it is Lewandowski and Bossie who are likely to draw the most concern.

Lewandowski was one of the most ubiquitous members of the 2016 Trump campaign but was fired that June amid disagreements with other people close to Trump. Lewandowski also had been charged with simple battery in Florida three months earlier after forcefully grabbing a reporter at a Trump campaign event; those charges were later dropped.

Bossie was hired by Trump as deputy campaign manager in September 2016 after years of work in Republican politics.

Lewandowski and Bossie have both been involved in efforts to contest the results of the 2020 presidential election. Both men also tested positive for the novel coronavirus after attending a large campaign party at the White House on election night.

The chief Pentagon spokesman, Jonathan Rath Hoffman, could not be reached for comment.