WASHINGTON — A U.S. military judge in Guantanamo Bay, Cuba, has scheduled hearings in early January for alleged 9/11 mastermind Khalid Sheikh Mohammed and two co-defendants. enter a guilty plea in exchange for a life sentence despite Defense Secretary Lloyd Austin’s effort to shake off the plea deals.

Wednesday’s move by Judge Matthew McCall, an Air Force colonel, in the government’s long-running prosecution of the Sept. 11, 2001, attacks that killed nearly 3,000 people signals a the deepening of the battle on the independence of the military commission from the Guantanamo naval base.

McCall has tentatively scheduled plea hearings to take place over a two-week period beginning Jan. 6, and Mohammed — the defendant accused of using commercial jets in the attacks — is expected to enter his plea first if Austin’s efforts to block fails.

Austin is seeking to scuttle the deals for Mohammed and co-defendants Walid bin Attash and Mustafa al-Hawsawi, which would set back more than 20 years of government prosecution efforts for a trial that carries the risk of the death penalty.

While government prosecutors negotiated the plea deals under the auspices of the Defense Department for more than two years and received the necessary approval this summer from the top official overseeing the Guantanamo prosecutions, the deals have sparked angry condemnation from Senators Mitch McConnell and Tom Cotton and other leaders. Republicans when the news broke.

Within days, Austin issued a order by throwing the bidssaying that the seriousness of the 9/11 attacks meant that any decision to waive the defendants’ possibility of execution would have to be made by him.

Defense lawyers argued that Austin lacked legal standing to intervene and that his move amounted to outside interference that could call into question the legal validity of the Guantanamo proceedings.

US officials created the hybrid military commission, governed by a mix of civilian and military laws and rules, to try people arrested in what the George W. Bush administration called the “war on terror” after the 9/11 attacks.

The al-Qaida attack was among the most damaging and deadly for the US in its history. The hijackers took over four passenger planes and flew them into the World Trade Center and the Pentagon, with the fourth landing in a field in Pennsylvania.

McCall ruled last week that Austin had no legal standing reject plea deals and that his intervention was too late because it came after approval from the top official at Guantanamo made them valid.

McCall’s ruling also confirmed that the government and higher authorities at Guantanamo agreed to clauses in the plea agreements for Mohammed and another defendant that prevent authorities from seeking possible death sentences again, even though the plea agreements guilty pleas were later dropped for some reason. The clauses seemed written in advance to try to address the type of battle that is happening now.

The Defense Department notified the families Friday that it will continue to fight the plea deals. The officials planned to bar the defendants from entering their pleas, as well as challenging the pleas and McCall’s ruling before a US military commission review court, they said in a letter to the families of the 9/11 victims.

On Wednesday, the Pentagon did not immediately respond to questions about whether it had filed an appeal.

While the families of some of the victims and others are adamant that the 9/11 prosecutions continue with trials and possible death sentences, legal experts say it’s not clear that could ever happen. If the 9/11 cases remove obstacles to trial, verdicts and sentences, the U.S. Court of Appeals for the District of Columbia Circuit would likely hear many of the issues in the course of any death penalty appeals.

The issues include the CIA’s destruction of interrogation videos, whether the rescinding of Austin’s plea deal constituted unlawful interference, and whether the men’s torture tainted subsequent interrogations by “clean teams” of FBI agents that did not involve violence.

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