Defense Secretary Robert Gates on Friday warned Congress not to mess with the military's "don't ask, don't tell" policy -- the ban on gays serving openly in the military until he can come up with a plan for dealing with potential opposition in the ranks.
In a strongly worded letter obtained by Fox News, Gates told the House Armed Services Committee that forcing policy changes on the military before it's ready would "send a very damaging message to our men and women in uniform."
"I strongly oppose any legislation that seeks to change this policy prior to the completion of this vital assessment process," Gates wrote to the panel's chairman, Missouri Democrat Ike Skelton. "Our military must be afforded the opportunity to inform us of their concerns, insights and suggestions if we are to carry out this change successfully."
Gay rights advocates want legislation this year that would freeze military firings of openly gay service members, and some senior Democratic senators have said they want to offer such a bill.
But other lawmakers, including Skelton, have said they are uneasy about lifting the ban and don't want to act before the force is ready.
Gates' letter provides Skelton and other unsettled Democrats political cover not to press the issue until after this year's midterm elections. Earlier this week, Skelton asked Gates in a letter to outline his views as the House committee prepares the 2011 defense authorization bill.
President Obama has said the 1993 law unfairly punishes patriotic Americans and asked Congress to repeal it.
Gates says he supports lifting the ban but wants to survey the troops first on how it should be done. He has ordered a study by Dec. 1 that will look at whether housing arrangements would have to be altered and gay partners would be allowed military benefits.
If Congress acts before then, "it would send a very damaging message to our men and women in uniform that in essence their views, concerns and perspectives do not matter," he told Skelton.
Defense officials hope the protracted timeline will also help troops adjust to the idea of serving with openly gay colleagues before they have to accept the change.
Sen. Carl Levin, the Michigan Democrat who heads the Senate Armed Services Committee, is expected to propose in the 2011 defense authorization bill a moratorium on gay firings in the military.
Fox News' Mike Emanuel and The Associated Press contributed to this report.