WASHINGTON (AP) — Democratic lawmakers on the House Intelligence Committee asked the Trump administration on Monday about its reasons for revoking the security clearances of 37 current and former national security officials.

In a letter to Director of National Intelligence Tulsi Gabbard, the lawmakers asked for the specific reasons for each revocations, and whether standard clearance review procedures were followed.

The Democrats also asked whether the government notified those affected before the revocations were announced, and whether the Trump administration considered the impact the revocations would have on national security.

So many revocations either reflects deep problems with government vetting or suggests the process has become politicized, the lawmakers wrote.

“Your move was therefore immensely consequential to the national security of the United States,” the Democrats wrote. “It is imperative that Congress be satisfied that you are not politicizing the work of the intelligence community or using the security clearance process for political ends.”

Gabbard has justified the revocations by saying the 37 current and former officials all either tried to politicize their work or failed to meet some other professional standard.

A spokesperson for her agency has said all relevant government agencies were notified of the revocations, and that no undercover spies were exposed by the move.

In a memo detailing the revocations, Gabbard accused those singled out of having engaged in the “politicization or weaponization of intelligence” to advance personal or partisan goals, failing to safeguard classified information, failing to “adhere to professional analytic tradecraft standards” and other unspecified “detrimental” conduct.

Gabbard’s memo did not offer evidence to back up the accusations.

The letter from the Democratic lawmakers seeks responses by Sept. 19. It was signed by U.S. Rep. Jim Himes of Connecticut, the senior Democrat on the House Intelligence Committee, as well as the 11 other Democratic lawmakers serving on the panel.