WASHINGTON (Reuters) -Boeing's head of government affairs and top lobbyist is leaving effective immediately, the planemaker's CEO told employees in an email Friday.

Ziad Ojakli will be replaced on an interim basis by Bill McSherry, who oversees the planemaker's state and local government operations, Boeing CEO Kelly Ortberg said in an email. Ojakli took over as head of Boeing government operations in September 2021 and previously headed Ford Motor and SoftBank government affairs offices.

Boeing has faced a difficult year after a door plug missing four key bolts blew off a new Alaska Airlines Boeing 737 MAX 9 jet at 16,000 feet in January.

Ojakli, who also served as an aide to former President George W. Bush, could not be reached for comment. Boeing declined to comment on the move.

The company has faced criticism from U.S. lawmakers on a number of fronts. Boeing's relationship with the U.S. government is crucial and it is a major defense contractor for the Pentagon.

Ortberg took over in August during ongoing investigations by the Justice Department and Federal Aviation Administration into the mid-air emergency. He has been working to repair Boeing's relationship with the FAA and lawmakers. This week he held another meeting with FAA Administrator Mike Whitaker in Seattle.

Ortberg also recently spoke with President-elect Donald Trump and discussed potential new tariffs on China, a person briefed on the matter said.

Last month, Boeing said its head of quality for commercial airplanes, Elizabeth Lund, would retire in December. Lund has spearheaded the planemaker's improvement plans. In September, Boeing said the head of its troubled space and defense unit was leaving immediately.

In July, Boeing finalized an agreement to plead guilty to conspiring to defraud the FAA and to pay up to $487 million. U.S. District Judge Reed O'Connor on Thursday rejected Boeing's agreement to plead guilty, faulting a diversity and inclusion provision in the deal.