Scott Mugno, the former FedEx official poised to win Senate confirmation to run the Labor Department’s safety and health agency, has informed the White House he no longer wants to join the administration, sources briefed on the matter told Bloomberg Law.

Mugno wrote to the White House and Labor Secretary Alexander Acosta May 14 to say he was pulling out of the process. Acosta, who has already seen six of his high-level political appointees depart since the start of 2019, was initially attempting to salvage Mugno’s nomination to run the Occupational Safety and Health Administration, one source familiar with the situation said. But the source, speaking on condition of anonymity to discuss ongoing agency deliberations, said Mugno’s decision is final.

“After 19 months of waiting for confirmation, Scott Mugno and his family decided it was best to move on to other pursuits,” a DOL source confirmed in a statement. “Recent confirmations of Cheryl Stanton and Bill Beach show progress in this process yet it is unfortunate to lose such a high-caliber candidate due to the existing backlog of nominations.”

A White House spokesman didn’t provide a comment.

The departure marks a significant loss for a labor secretary attempting to overcome the challenges of advancing policy without Senate-confirmed leadership in key offices. The OSHA post has been vacant for the entirety of the Trump administration, which business stakeholders believe has stalled the agency’s ability to reverse the more worker-friendly approach under Obama.

Mugno’s departure comes the same week Bloomberg Law reported that Acosta’s Chief of Staff Nicholas Geale will be resigning after a White House investigation found he had mistreated staff and misled White House officials about the DOL’s progress on regulations. It’s not clear if the latest evidence of administration discord on labor policy played a role in Mugno’s decision to add his name to the growing list of people no longer interested in serving in a Trump DOL.

Mugno, after holding out for 17 months as the OSHA nominee, was finally poised to receive a confirmation vote before the full Senate. Several sources close to the situation considered Mugno the next DOL appointee to hear his name called on the chamber floor, where he would’ve faced a near-certain confirmation in the GOP-controlled Senate.

The perception that he was weeks from arrival at OSHA made sources close to Mugno baffled to hear reports of his plans to withdraw.

“It would be a shame if he did that because he certainly is the ideal candidate for that position,” said Marc Freedman, vice president of employment policy at the U.S. Chamber of Commerce.

After Trump nominated him in 2017, Mugno retired from a 24-year career at FedEx Ground and Express. The last six years he was the shipping company’s vice president of safety, sustainability, and vehicle maintenance.