Attorney General John Ashcroft asked a federal district court Thursday to dismiss a lawsuit that would override his efforts to block Oregon's unique assisted suicide law.

Ashcroft's attorneys reiterated his main argument against the law, that taking the life of a terminally ill patient is not a "legitimate medical purpose" for federally controlled drugs.

They argued that the district court has no standing to hear the case involving the federal Controlled Substances Act. And they rejected Oregon's claim that the attorney general violated the Constitution when he took steps last fall to effectively overrule the state's assisted suicide law.

In November, Ashcroft sent a memo to the Drug Enforcement Administration saying that doctors who use federally controlled drugs to help patients die, as Oregon law allows, will lose their license to prescribe the drugs. Typically, terminally ill patients take federally controlled barbiturates to end their lives.

The state filed a suit to block his directive.

U.S. District Judge Robert E. Jones granted the state's request for a temporary restraining order on Nov. 8. Jones could issue his final ruling this spring, though appeals could take years.

The state has asked the judge to rule quickly under a summary judgment — a motion the Justice Department is also fighting.

Kristen Grainger, executive assistant to Oregon Attorney General Hardy Myers, said most of the arguments that the Justice Department made Thursday were to be expected. "There weren't many surprises."

However, she noted, the federal attorneys had stopped questioning Oregon's standing to file the suit. In the past, they had argued that the state couldn't show it was harmed and had no right to sue.

To counter that, Myers' office has said that it had a responsibility to defend the physician-assisted suicide law — twice approved by Oregon voters.

At least 91 people have ended their lives under a doctor's care since the law took effect in 1997, according to a survey published recently in a medical journal. Twenty-one did so last year.

To request a fatal prescription, a patient must be at least 18 and an Oregon resident, capable of communicating health care decisions and diagnosed with an illness that will lead to death within six months.