FORT HOOD, Texas — Defense attorneys ordered to help the Army psychiatrist charged in the deadly 2009 Fort Hood shooting rampage said Tuesday that it would be unethical to give him their legal advice and opinions while he's representing himself at his upcoming murder trial.

After allowing Maj. Nidal Hasan to serve as his own attorney, Army judge Col. Tara Osborn last week said his former attorneys would stand by and help him if he requests it.

On Tuesday, former lead defense attorney Lt. Col. Kris Poppe said complying with the judge's order would be unethical because it seems to have no limits and requires the attorneys to give legal opinions in addition to doing research.

Hasan told the judge Tuesday that a paralegal did research about his defense strategy over the weekend, instead of the three attorneys. He said the attorneys refused to give their opinions when he asked what evidence and witnesses would best help his case.

"They don't believe that I should go forward with (this defense) ... and by helping me, they believe that crosses an ethical line," Hasan told the judge during the one-hour hearing.

Osborn had asked Hasan for more information, including a legal basis and any evidence to support his "defense of others" strategy, which would require him to prove that the shootings were necessary to prevent the immediate harm or death of others. Hasan has said he shot U.S. troops on the Texas Army post to protect Taliban leaders in Afghanistan.

Hasan, an American-born Muslim, faces the death penalty or life without parole if convicted in the rampage that left 13 dead and nearly three dozen wounded.

It's unclear when the judge will rule on whether to allow Hasan's defense strategy or on his request for a three-month trial delay. Jury selection was to begin last week, with testimony starting in early July. But that has been delayed since various issues have arisen after Hasan requested and was allowed to be his own attorney.

On Tuesday, Osborn refused Poppe's request for a closed hearing, but she gave defense attorneys about 24 hours to submit motions supporting their argument that they cannot comply with the judge's orders to help Hasan. Osborn said it's within a standby attorney's scope to give opinions to a defendant representing himself.