Lawyers for the Tucson shooting rampage suspect asked a federal court again Friday to stop his forced medication at a medical facility in a Missouri prison.

Jared Lee Loughner's lead attorney, Judy Clarke, wrote in an emergency motion that the ongoing forced medication of her client is unlawful. She said Loughner will suffer "irreparable harm" unless the prison is ordered to cease giving him a daily "four-drug cocktail," or at least start tapering him off it.

Loughner, 23, has been at the Springfield, Mo., facility since May 27 after he was found to be mentally unfit to stand trial. Experts have concluded he suffers from schizophrenia and are trying to restore his competency.

Loughner has pleaded not guilty to 49 charges stemming from the Jan. 8 shooting at a political event outside a northwest Tucson supermarket. The rampage left six people dead and 13 wounded, including Rep. Gabrielle Giffords, who is still recovering.

Prison officials have forcibly medicated Loughner with psychotropic drugs after concluding he posed a danger at the facility. Federal prosecutors have previously argued Loughner should remain medicated because his mental and physical condition has been rapidly deteriorating.

Clarke said Loughner "has an exceptionally strong interest in not being executed." But she noted it is "no secret" that the government may seek the death penalty if the case is eventually tried.