“Going into this process, I expected tough questions about how to best care for our veterans, but I did not expect to have to dignify baseless and anonymous attacks on my character and integrity,” Jackson said in a statement.

“The allegations against me are completely false and fabricated,” he said. “If they had any merit, I would not have been selected, promoted and entrusted to serve in such a sensitive and important role as physician to three presidents over the past 12 years.”

Jackson’s failed nomination is the latest instance of staff turmoil in President Donald Trump’s administration, which has seen record turnover and a series of personnel scandals. Jackson was nominated to replace former Secretary David Shulkin, who Trump fired in March after a damning inspector general report alleging misuse of taxpayer funds.

Trump’s decision to nominate the White House doctor to run the Veterans Affairs Department immediately raised questions among lawmakers who expressed concern about Jackson’s background and experience.

Democrats and Republicans on the Senate’s Veterans Affairs Committee delayed a planned hearing on Jackson’s nomination after hearing allegations about problems within his office. The New York Times and CBS News, citing unnamed officials briefed on the matter, reported they included overseeing a hostile work environment as the White House doctor, allowed the overprescribing of drugs and drank on the job.

Jackson denied the allegations.

“In my role as a doctor, I have tirelessly worked to provide excellent care for all my patients,” he said in the statement. “In doing so, I have always adhered to the highest ethical standards.”

“Unfortunately, because of how Washington works, these false allegations have become a distraction for this President and the important issue we must be addressing – how we give the best care to our nation’s heroes.”

Trump said at a news conference with French President Emmanuel Macron on Tuesday that he was unaware of the allegations, but that he had advised Jackson earlier in the day to withdraw.

“I said to Dr. Jackson, what do you need it for?” Trump said. “I don’t want toput a man through a process like this. It’s too ugly and disgusting.”

He later added, “I really don’t think personally he should” continue in the running for the post “but it’s totally his, I would stand behind him, totally his decision.”