Washington (CNN) -- One of the most bitterly contested issues facing the soon-to-be adjourned Congress will take center stage next week when military leadership is called to testify about repealing the military prohibition on gay troops serving openly.
The hearings will last two days: First, the Senate Armed Services Committee will hear from Secretary of Defense Robert Gates and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and the next day, it will hear from the military heads of the four military services. The hearings start just two days after Gates sends senators the long-awaited Pentagon report he commissioned on how the military will cope with a repeal of its "don't ask, don't tell" policy.
The committee's ranking Republican, Sen. John McCain, R-Arizona, will get a chance to grill Gates and the report authors who will appear with him and Mullen. He may ask why a survey of active duty military and families -- a central part of the report -- did not directly ask whether they supported changing the present policy, but focused instead on how it should be changed. McCain wrote a letter to Gates about this back in September.
In a response written in October, Gates told McCain that it was not part of the charter of Pentagon's so-called working group to poll the troops on whether the "don't ask, don't tell" policy should be repealed.
"I do not believe that military policy decisions should -- on this or any other subject -- be subject to referendum of Servicemembers," Gates wrote.
His letter to McCain has not been released but was obtained by a liberal group that supports the ban. A Pentagon source confirmed the accuracy of the quote.
Gates said the survey will allow him, Mullen and the chiefs of the individual services to understand how a policy change may affect "unit cohesion, military readiness and effectiveness, recruiting and retention and family readiness."
The greatest political drama in the hearings may come Friday, December 3, when the top brass of the Army, Navy, Air Force and Marines sit shoulder-to-shoulder at the witness table. In public comments over the last year, they have either directly opposed or been unenthusiastic about the policy change, at least until the Pentagon report was finished and released.
Marine Commandant James Amos has said that he opposes the change while the U.S. is fighting in Afghanistan because of its potential negative effect on unit cohesion. There will be two Marines on the second day of hearings since the vice chairman of the Joint Chiefs, Gen. James Cartwright, will be part of the panel answering senators' questions.
Also testifying will be Gen. George Casey, the Army chief of staff. He has said he is on board with Gates in considering the effect of the repeal. But committee members may remind him of something he told them before.
"I do have serious concerns about the impact of the repeal of the law on a force that's fully engaged in two wars and has been at war for eight and a half years," Casey said earlier this year.
Once the report is delivered Tuesday and the hearing room falls silent after Thursday and Friday, the spotlight will turn to Senate Majority Leader Harry Reid. He will decide how the issue will move forward, whether to keep it part of the Defense Authorization Bill or whether to strip it off for a separate vote.
But the calendar could be the biggest factor weighing on this law being repealed or upheld. With just weeks left for this Congress with its significant Democratic majority, leadership will need to decide if it has the time, amid other priorities it wants considered, to mire the Senate in debate about "don't ask, don't tell."