Sen. John McCain, once an ally in President Obama's effort to close the terrorist detention facility in Guantanamo Bay, has tired of White House delays, and says he's no longer sure the administration can deliver any plan that can win support.

The Arizona Republican and former campaign opponent of Obama supports closing the prison, as long as the prisoners are kept under supervision of the Defense Department. He has previously worked with the administration to find a way to fulfill the president's 2008 campaign promise of closing the prison.

But now, he says the administration has lost all credibility with him because they haven't lived up to previous promises on the timing of the plan's submission to Congress.

"It was a short time ago when the secretary of defense and the president's adviser, Lisa Monaco, were in my office, and they said we'll have a plan for you in a few days," he told the Washington Examiner. "They no longer tell the truth. They no longer have any credibility with me."

McCain also predicted that the courts would shoot down any attempt by President Obama to pull an end-run around Congress and issue an executive order to close the facility.

"We'll go to court, and he'll be defeated in court again just as he is on the executive order on immigration," McCain said. "He has total disregard for the Constitution of the United States."

The Obama administration for months has said it is wrapping up work on its plan to shutter the Guantanamo Bay facility, along with cost estimates for doing so. The Department of Defense must submit the plan to Capitol Hill to review, and the White House has repeatedly said it plans to send it very soon.

Outside groups following the issue closely tell the Examiner the plan could come within days. But McCain isn't the only one losing patience, as key Democratic members of Congress say they have no indication on when the report will arrive.

Rhode Island Sen. Jack Reed, the ranking Democrat on the Armed Services panel, says he has no information on timing.

Sens. Dianne Feinstein, D-Calif., the ranking member of the Intelligence Committee, as well as Bill Nelson, D-Fla., a senior member on the Armed Services panel, also don't have an inside track on when it will land on Capitol Hill. Those same Democrats also are reluctant to talk about how they would react to Obama acting unilaterally to close the prison through an executive order.

"I can't respond to that, I just don't know," Feinstein said when asked.

"I haven't examined that," Nelson replied.

Reed said only that the first step is for the administration to submit its closure plan to Congress, and for Republicans and Democrats to debate the plan.

The president has accelerated his transfer of Guantanamo Bay prisoners to other countries this year, bringing the number of detainees remaining at the military prison down to 93. Still, there is a core group numbering less than 50 who likely are too dangerous to release.

Obama's plan will provide the details of moving the group to prisons in the United States. The possibilities include the federal Supermax prison in Florence, Colo., the military prison in Leavenworth, Kansas, and the Naval Consoliated Brig in Charleston, North Carolina.

"Frankly, once the population has been moved it, closing it becomes a technical issue," Reed said. "Part of this plan would be the location, what would the conditions be, how many would be transferred, any guarantees for the long-term incarceration and the security of that community. All that has to be at least discussed if not specifically designated."

Once the president submits his plan to Congress, Reed said, "that places the burden on the [GOP] opposition to say, 'Why don't you want to follow this plan? What is your plan if you truly want to close Gitmo?'"

But most Republicans would like to see the prison remain open, and warn that closing the facility would push more terrorist suspects overseas to return to the battlefield or to prisons in communities in the U.S. that don't want them.

McCain and others who want to close the facility are dead-set against a executive action in the waning months of Obama's time in office, even though they are bracing for it. During an end-of-the-year press conference in December, Obama declined to say whether he would issue an executive order to close the island prison, arguing he would wait until Congress has reviewed his closure plan and weighed it.

"I'm not going to automatically assume that Congress says 'no,'" Obama said about the plan he is still creating. "I think it's fair to say that there's gonna be significant resistance from some quarters" to his ultimate closure plan."

"[W]e will wait until Congress has said definitively 'no' to a well-thought-out plan with numbers attached to it before we say anything definitive about my executive authority here," he said. "I think it's far preferable if I can get stuff done with Congress."