Of the 29 who led the uprising on July 27, 2003, only Navy Lt. S/G Antonio Trillanes IV and Army Capt. Milo Maestrecampo were recognized by the military tribunal as having faced arraignment already.
Defense lawyers said Abu must immediately order the release of the other 27 military officers once the General Courts Martial recommends it.
"This is a challenge for him (Abu)," defense counsel Roel Pulido told a news conference in Quezon City.
"If he really is an officer and a gentleman, he should be the one to uphold the law. Before his term expires on Aug. 15, he should show that no matter how painful the decision will be for him (he should make it)."
The leaders of the Magdalo group are expecting their release when their military trial resumes on Monday.
Armed Forces spokesman Brig. Gen. Jose Angel Honrado meanwhile warned soldiers yesterday to air their gripes in the proper forum amid persistent coup rumors.
Voting is the only permissible political activity of soldiers, he added.
Honrado appealed to retired generals, a good number of whom have been critical of present military policies, for help in resolving the problems in the uniformed services.
"Like any other organization, the AFP is not immune from feelings of discontent and dissatisfaction from within its members," he said.
As Armed Forces chief, Abu has the authority to convene the General Court Martial and its judgment is subject to his review and approval.
Pulido and another defense lawyer, Theodore Te, have expressed apprehensions that Abu might block the release of the 29 detained military officers, judging from his previous actions.
Te said Abu tried to block the granting of bail to the mutiny leaders before the Makati Regional Trial Court where they are also facing charges of coup d’état, as defined in the Revised Penal Code, by testifying for the prosecution.
"I would expect General Abu to rise above all that and to say: ‘Hey, I will be a professional soldier. Even if I testified against these people, the law tells me that I have to dismiss these cases,’" Te said.
At the instance of military prosecutors late last year, Abu approved the re-filing of the charges against some 300 soldiers who took part in the failed uprising, he added.
Abu could not be reached for comment, and his spokesman declined to react to the defense lawyers’ statement.
Pulido cited the case of Lt. Col. Marcelino "Jake" Malajacan, who has been detained for four years, even after the two-year prescription under the Articles of War had lapsed because then Armed Forces chief Gen. Lisandro Abadia had sat on a recommendation for his release.
The charge for violation of Article of War 96 (conduct unbecoming an officer and a gentleman) against the 27 military officers lapsed after military prosecutors failed to have them arraigned within the two-year period.
The prescribed period expired midnight Tuesday. However, Te said his client, Maestrecampo, had not yet been arraigned despite being read the charges as he only entered a special plea, not a plea to the charge.
On Thursday, Pulido and Te formally petitioned the special general court martial to dismiss the charges against their clients and not to consider Maestrecampo as having been arraigned.
"Accused… respectfully pray that this court order the immediate dismissal of the charge and specification for violation of the 96th Article of War against all the accused… and order that the proceedings against them be terminated," read the petition.
The 29 military officers remain in military detention despite being granted bail by the Makati RTC.