The two Republicans are calling on Gingrich to resign because of a "lack of leadership" concerning the conferences.

"In a directive to the department dated January 29, 2009, Mr. Gingrich initiated for himself the ultimate responsibility on behalf of VA for approving conferences involving 100 or more employees," the Republicans write.

Burr and Miller continue Gingrich's approval of the $8-million budget for the conferences where the inspector general found unnecessary spending shows that the chief of staff treated his responsibility far too "casually."

"We can only conclude that Mr. Gingrich's role was merely to provide the appearance of oversight, nothing more," Burr and Miller wrote.

The two Republicans conclude the letter arguing that Gingrich's removal would send a clear message to the rest of the Department of Veterans Affairs.

"Accountability begins at the top. In this instance, the VA Chief of Staff cavalierly approved an exorbitant conference budget under the guise of a process meant to safeguard against that very occurrence. A message must be sent to all VA employees that perfunctory execution of so great a responsibility is inexcusable at any time, and at any level. Mr Gingrich's removal as chief of staff is the unequivocal way to deliver that message of accountability."

In August, Sen. Patty MurrayPatricia (Patty) Lynn Murray30 million people will experience eating disorders — the CDC needs to help Mulvaney remarks on Trump budget plan spark confusion Overnight Finance: Mulvaney sparks confusion with budget remarks | Trump spars with lawmakers on tariffs | Treasury looks to kill 300 tax regs | Intel chief's warning on debt MORE (D-Wash.), the chairwoman of the Veterans Affairs committee, said she was "deeply disturbed" over initial reports of wasteful spending at the conferences.

Read the letter below.

Sen. Burr and Rep. Miller call on VA CoS resignation