Washington (CNN) -- Defense Secretary Robert Gates will unveil the Pentagon's plan to prepare for repealing the controversial "don't ask, don't tell" law regarding gay soldiers at a committee hearing Tuesday, a Pentagon spokesman said.

"The Defense Department leadership is actively working on an implementation plan and the secretary will have more to say about this next week," Pentagon press secretary Geoff Morrell said on Thursday.

President Obama said in his first State of the Union address Wednesday night that he would work with Congress and the Pentagon this year to repeal the law that prohibits military members from acknowledging openly that they are gay.

According to the Senate Web site, the Senate Armed Services Committee has scheduled an hour to discuss the issue at Tuesday's hearing on the fiscal year 2011 defense budget, which Gates will attend.

The committee revised its schedule for the hearing, announcing that Gates and Joint Chiefs of Staff Chairman Adm. Mike Mullen will testify on the budget, as planned, as well as the "don't ask, don't tell" issue.

Gates and Mullen are not expected to offer a specific legislative proposal to repeal the law, but rather to detail some of the preliminary steps that need to be taken inside the military in advance of formulating a legislative plan.

Gates will discuss options for more "humanely" implementing the current ban, for example, according to a senior Pentagon official. The secretary asked his general counsel's office for options six months ago including how to possibly not expel personnel whose homosexuality is revealed by third parties, the source said.

The 1993 law bars gay men and lesbians in the military from revealing their sexual orientation, and prevents the military from asking about it.

Another military official familiar with the discussion said some of the issues to be considered include the cost of implementing a new policy, benefits for gay spouses, potential hate crimes, and even logistical questions such as the possible need to renovate barracks to separate straight and gay troops.

According to the official, the idea of separate housing or showers was not considered a serious possibility, but would be discussed in order to rule it out.

Previously, Gates has said the transition from the existing law should be done gradually and "very, very carefully."

"The president has been clear about where he wants to go and what he thinks needs to be done," Gates said in April at the Army War College when asked about changing the law. "But I think that he is approaching this in a deliberate and cautious manner, so that if we do go down that road, we do it right and we do it in a way that mitigates any downsides, problems that might be associated with it."

At least one member of the Joint Chiefs of Staff -- Gen. James Conway, commandant of the Marine Corps -- has expressed reservations in the past about repealing the law.

In November, Conway said through a spokesman: "Our Marines are currently engaged in two fights, and our focus should not be drawn away from those priorities."

Some Congressional opposition already is clear. Sen. John McCain, R-Arizona, a former Navy pilot, released a statement after Wednesday night's State of the Union address saying "it would be a mistake" to repeal the law.

"This successful policy has been in effect for over 15 years, and it is well understood and predominantly supported by our military at all levels," McCain's statement said, later adding: "At a time when our Armed Forces are fighting and sacrificing on the battlefield, now is not the time to abandon the policy."

Others support the change. Gen. John Shalikashvili, former chairman of the Joint Chiefs of Staff, said it was time to repeal the law.

"As a nation built on the principal of equality, we should recognize and welcome change that will build a stronger more cohesive military," Shalikashvili said in a letter sent to Sen. Kirsten Gillibrand, D-New York, who supports repealing the policy.

The Servicemembers Legal Defense Network, an organization that works with those affected by the "don't ask, don't tell" law, praised Obama's call for repeal.

"We very much need a sense of urgency to get this done in 2010," the group said, later adding: "The American public, including conservatives, is overwhelmingly with the commander in chief on this one."