Both Democrats and Republicans serving on the Senate Committee on Veterans Affairs, including Sen. Jon Tester, are asking the White House to provide documentation pertaining to President Donald Trump's nominee to head the VA.

The Senate committee on Tuesday postponed its scheduled hearing to consider the nomination of Rear Adm. Ronny Jackson to serve as VA secretary, and instead asked the president for “all documentation” relating to Jackson's service in the White House Medical Unit and physician to the president.

“The Senate Committee on Veterans Affairs is postponing the hearing to consider the nominee to be secretary of the U.S. Department of Veterans Affairs in light of new information presented to the committee,” Tester said in a joint statement with Sen. Johnny Isakson, R-Ga., on Tuesday.

“We will continue looking into these serious allegations and have requested additional information from the White House to enable the committee to conduct a full review.”

While Tester didn't detail the allegations facing Jackson, national news outlets say whistleblowers told the Senate committee that Jackson's questionable behavior included excessive drinking and a “toxic” work environment under his leadership.

After postponing Tuesday's hearing, Tester and Isakson sent a letter to Trump seeking all information regarding any improper conduct pertaining to Jackson’s service in the White House Medical Unit and as physician to the president.

“We further request any and all allegations and documents, including those developed during the course of an investigation, that are in the custody of the White House Military Office, the White House Medical Unit, or any office in the Executive Office of the President that were never communicated to the Department of Defense or Offices of Inspector General,” the letter states.