Prospects for adoption of an amendment repealing the military’s “don’t ask, don’t tell” policy got ever stronger Wednesday when a key Democratic holdout on the Senate Armed Services Committee announced he would support the proposal, and Majority Leader Harry Reid (D-Nev.) committed to pushing the issue on the floor.

Sen. Ben Nelson said in a statement that — after talking with Defense Secretary Robert Gates, who has grudgingly signed off on compromise repeal language — that he would support the amendment to the defense authorization bill.

“I don’t believe that most Nebraskans want to continue a policy that not only encourages but requires people to be deceptive and to lie,” the Nebraska Democrat said. “The ‘don’t ask, don’t tell’ policy does just that. It also encourages suspicion, and senior officers to look the other way. In a military, which values honesty and integrity, this policy encourages deceit.”

Sen. Joe Lieberman (ID-Conn.), with the backing of Armed Services Chairman Carl Levin (D-Mich.), plans to offer an amendment Thursday during the Armed Services panel’s markup of the defense bill that would repeal the 1993 law.

Regardless of the outcome in committee, Reid said Wednesday that he was committed to trying to include the repeal language in the bill that passes the Senate.

“If it’s in the committee, of course,” Reid said, noting that he himself was a longtime advocate of repealing the policy. “If it isn’t, there will be an amendment anyway.”

Compromise language hammered out this week with the White House would delay implementation until a Pentagon study is complete and make the repeal contingent on the president and top military officials certifying that the repeal would not hinder military readiness.

Nelson said the compromise “shows that Congress values the Pentagon’s review that will include the advice and viewpoints from our men and women in uniform, from outside experts and from the American people about how to implement the repeal. It rests ultimate authority to make this change with our military leaders.”

Nelson added, “I believe this is the right thing to do.”

With Nelson on board, it is looking increasingly likely that repeal backers will win adoption of their amendment. Only one of the 16 Democrats on the panel, Virginia Sen. Jim Webb, has come out publicly against the repeal, although at least one more, West Virginia Sen. Robert Byrd, had not yet taken a position as of midday Wednesday.

Republican Sen. Susan Collins of Maine has said she will vote for the proposal, giving Democrats, who have a four-seat edge on the panel, more than enough votes if no other members of the majority defect.

“We’re expecting tomorrow to be successful,” a Senate aide said, adding that leadership had indicated its support for the proposal, which also could come to a vote on the House floor before week’s end.