The top congressional Democrats on defense issues are seeking answers from Defense Secretary James Mattis on his recommendations to President Trump against allowing transgender people in the military, which seemed to be based on junk science and were used by the administration to reaffirm its ban on their service.

In a joint letter to Mattis dated April 11, the quartet of Democrats say they were “surprised and disappointed” by Mattis’ conclusions against transgender service, which the White House made public late last month in an announcement renewing Trump’s ban.

“In our view, these recommendations contradict previous findings from the Department of Defense and the professional medical community,” the letter says. “As the president has empowered you to implement appropriate policies governing service by transgender individuals, we feel it imperative that we explore the factual bases behind your recommendations.”

The letter is signed by Rep. Adam Smith (D-Wash.), top Democrat on the House Armed Services Committee; Sen. Jack Reed (D-R.I.), top Democrat on the Senate Armed Services Committee; Rep. Jackie Speier (D-Calif.), and Sen. Kirsten Gillibrand (D-N.Y.). Both Speier and Gillibrand introduced bills in their respective chambers of Congress against Trump’s transgender military ban, but those measures also sought to codify Mattis’ review before it was completed.

“There are currently thousands of transgender individuals openly serving in the military with bravery and distinction,” the letter says. “There has been no indication that this has had an impact on overall readiness. All individuals who are willing and qualified should be able to volunteer to serve, regardless of their gender identity.”

The letter comes on the heels of objections to Mattis’ recommendations and Trump’s transgender ban from the American Medical Associations, which asserted the Pentagon “mischaracterized and rejected” medical research in its conclusions, as well as the American Psychological Association and two former U.S. surgeons general.

The conclusions Mattis reached are different from those during the Obama era under then-Defense Secretary Ashton Carter, who declared transgender people should be able to serve in the U.S. military after his own year-long review. Trump would later reverse this action.

Observing Mattis made his recommendations after he convened a “panel of experts” on transgender military service, the lawmakers pose six questions to the Pentagon about this review process.

1. Who was on the Panel of Experts?
2. Who did the Panel consult with?
3. Did the Panel consult with the American Psychiatric Association, American Psychological Association or American Medical Association or any other medical professionals with expertise in gender dysphoria?
4. In your view, what are the substantial risks associated with the accessions and retention of transgender persons? Can you please provide any examples that since June 30, 2016 these issues have arisen within the military and describe how the DOD or services handled these situations?
5. In your view, what are the specific issues that could undermine readiness, disrupt unit cohesion, and impose an unreasonable burden on the military? Can you please provide any examples that since June 30, 2016 these issues have arisen within the military and describe how the DOD or services handled these situations?
6. Were any government officials outside of DOD or the Department of Homeland Security (DHS) involved in the Report or your Memorandum to the president? If so, who were these officials and what was the basis for their involvement?

Additionally, the letter requests “the specific medical and scientific data that supported the conclusions contained in your memorandum.”

The administration has made conflicting statements on whether or not officials outside the Pentagon influenced the panel of experts. The White House told the Washington Blade the Pentagon made the conclusions “without regard to any external factors,” but Pentagon spokesperson Dana White said “it was a coordinated effort with the White House as well as the Department of Justice.”

Sources have told the Blade the military joint chiefs weren’t briefed before the Trump went public with the reaffirmation of his ban last month. A Pentagon spokesperson nonetheless said their representatives had input on the process leading to the Mattis recommendation.

Despite Mattis’ recommendations and Trump’s reaffirming of his transgender ban, the courts have banned the administration from enforcing it as a result of litigation from LGBT legal groups filed after Trump first announced via Twitter in July he’d ban transgender people from the military “in any capacity.”

A Pentagon spokesperson confirmed to the Washington Blade receipt of the letter from congressional Democrats, but had no immediate comment.