U.S. Office of Government Ethics director Walter Shaub Jr. resigned from his position yesterday (July 6).

As Time reports, Shaub’s resignation comes after months of fighting to make President Donald Trump and his administration comply with the rules set by the ethics office. From refusing to discipline advisor Kellyanne Conway for promoting Ivanka Trump’s clothing line to Trump’s refusal to pull out of his business interests, the administration has continually ignored Shaub’s authority. His last day will be July 19. Trump will nominate a replacement.

Shaub posted his resignation letter to Twitter:

 

While the letter doesn’t go into great detail about his reasons for leaving, one key portion says it all: “[My staff is] committed to protecting the principle that public service is a public trust, requiring employees to place loyalty to the Constitution, the laws and ethical principles above private gain.” Coupled with a statement released by his new employer, there is no doubt why he is leaving his post in an administration that has shown a willingness to flout the rules at every opportunity.

“I have had the honor and privilege of serving the American public at the U.S. Office of Government Ethics under three presidents—George W. Bush, Barack Obama and Donald Trump,” Shaub said in the statement from nonpartisan nonprofit The Campaign Legal Center. “In working with the current administration, it has become clear to me that we need improvements to the existing ethics program. I look forward to working toward that aim at Campaign Legal Center, as well as working on ethics reforms at all levels of government.”