The Defense Department announced Wednesday that 400,000 servicemembers are being surveyed on its “Don't Ask, Don't Tell” policy.

The survey is part of the military's comprehensive review of the policy that bans gay troops from serving openly in the military.

The review was ordered by Defense Secretary Robert Gates and is expected to be completed by December 1. Army General Carter F. Ham, commander of the U.S. Army Europe, and Jen Johnson, the Pentagon's top lawyer, head the review panel.

“The voice of the servicemembers is still vitally important,” Ham told the military's American Forces Press Service.

The assessment will continue even as Congress debates whether to repeal the law. House members voted in favor of repeal in May, while senators are expected to take up the issue this month. The legislation, however, gives the military and President Obama final say on the specifics of repeal.

“This is draft legislation, it is not yet enacted into law,” Ham added, “and there are several hurdles yet to come.”

Half of the surveys were sent to active-duty personnel, and half were sent to reserve troops. Another 150,000 surveys will be mailed to military spouses shortly. Participants are directed to a secure website where they are asked to answer roughly 90 questions, including whether or not the ban should be lifted.

Ham also announced an online tool that allows gay and lesbian troops to anonymously comment on the policy.

“It is vitally important that servicemembers continue to be open and frank and totally honest with us in their feedback,” Ham said. “That certainly has been the case to date, whether it's been a large-group session or a small group or the online inbox.”