WASHINGTON — Hours after White House officials asserted that their pick for Veterans Affairs secretary has undergone “more vetting than most nominees,” Senate Democrats released a list of 20 unresolved allegations against the would-be Cabinet official they say must be answered before a confirmation hearing.

The charges include accusations that White House physician Ronny Jackson, an active-duty Navy rear admiral, wrote false prescription orders for himself and others, undermined superiors and subordinates to cover his mistakes, and frequently drank while on duty, one time crashing a government vehicle while intoxicated.

Senate Veterans’ Affairs Committee ranking member Jon Tester, D-Mont., said the accusations “have raised serious concerns about Jackson’s temperament and ethics, and cast doubt on his ability to lead the second largest agency in government.”

Earlier this week, committee officials postponed Jackson’s scheduled confirmation hearing for Wednesday amid concerns that White House officials had not properly vetted a host of concerns with the 23-year military officer.

Trump’s Ronny Jackson disaster will make fixing the VA a lot harder The department, already dealing with years of negative attention, is now embroiled in a leadership scandal that again threatens its reputation.

Jackson was a surprise pick by President Donald Trump to replace former VA Secretary David Shulkin, who was fired over Twitter last month. Jackson has previously interviewed for the VA’s top health job, but withdrew his name from the post and has had little direct work with VA operations during his military career.

During a press conference Wednesday, White House Press Secretary Sarah Sanders noted that Jackson has served as physician to three presidents, which has prompted more scrutiny than nearly any other administration nominee.

“Given his unique position of trust and responsibility, Dr. Jackson’s background and character were evaluated during three different administrations,” she said. “Dr. Jackson has had at least four independent background investigations conducted during his time at the White House, including an FBI investigation conducted as part of the standard nomination vetting process.

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“During each of those investigations, Dr. Jackson received unanimous praise from dozens of witnesses, and the investigations revealed no areas of concern.”

But Tester and other Senate Democrats have said nearly two dozen whistleblowers have come forward to them since Jackson’s nomination, detailing a host of allegations. White House officials thus far have been unable or unwilling to respond to the charges.

They include:

— “Multiple individuals cited the nickname ‘Candyman’ used by WH staff (for Jackson) because he would provide whatever prescriptions they sought without paperwork.”

— “Jackson would have staff write scripts for each other to give to non-beneficiaries.”

— “Missing Percocet tabs once threw (the White House Military Office) into a panic. It turned out Jackson had provided a large supply to a staffer.”

— “Jackson was viewed as someone who ‘would roll over anyone,’ … a ‘kiss up, kick down boss,’ and ‘put his needs above everyone else’s.’”

— “Multiple incidents of drunkenness on duty were described to committee staff.”

— “On at least one occasion, Dr. Jackson could not be reached when needed because he was passed out drunk in his hotel room.”

— “At a Secret Service going away party, Jackson got drunk and wrecked a government vehicle.”

Rear Adm. Ronny Jackson, center, President Donald Trump's choice to be VA secretary, walks down a stairwell as he leaves a Senate office building after meeting with senators on April 24, 2018. (J. Scott Applewhite/AP)

The latest round of allegations prompted Rep. Tim Walz., D-Minn., and ranking member of the House Veterans’ Affairs Committee, to call for Jackson to withdraw his name from consideration for the top VA post.

“Not only does Adm. Jackson lack the management experience necessary to successfully lead the 360,000-person, nearly $200 billion federal agency, it is apparent there are also serious questions about his character and job performance,” he said in a statement.

Sanders said that “none of those things have come up” in previous background checks, and the White House is continuing to investigate it. But she also said senators should move forward with a confirmation hearing.

A day earlier, Trump suggested the allegations were the product of Senate Democrats working to undermine his VA agenda and his presidency as a whole. But Senate Republicans have also expressed multiple concerns about Jackson’s nomination, and Republican leaders signed off on the hearing postponement.

Trump also said he doesn’t see why Jackson would stay in the confirmation process, but will leave the decision to him.

“The fact is I wouldn’t do it,” Trump told reporters on Tuesday. “What does he need it for? To be abused by a bunch of politicians that aren’t thinking nicely about our country. I really don’t think personally he should do it, but it’s totally his decision.”

He also called Jackson “one of the finest people I have met.”

The earliest senators could hold a confirmation hearing would be the second week of May, but that timetable seems unlikely given the numerous questions surrounding Jackson’s background.

In an brief interview Tuesday, Jackson told MSNBC that he is “looking forward to the hearing so we can sit down and I can explain everything and answer all of the senators’ questions.”