Several Republican senators will try to set an official policy this week on the treatment of detainees in the war on terror, putting them on a collision course with President Bush, who has threatened to veto any such legislation.
Congress has never specifically authorized the long-term detention of people captured as part of the war on terror, and reports of abuses have made some legislators say the time has come to set specific standards for how long prisoners can be held and how they must be treated.
Sen. Lindsey Graham, South Carolina Republican, will introduce an amendment to the pending defense bill that he says would strengthen the Bush administration's hand by officially authorizing the government to hold detainees at Guantanamo Bay, Cuba.
"Without congressional authority, we run a real risk a federal court will either take over or impede our efforts at Gitmo," Mr. Graham said.
His amendment is expected to officially define "enemy combatants," a term not used in the Geneva Conventions, and to state conditions for their detention and release.
Meanwhile, Sen. John McCain, Arizona Republican, is working on an amendment that sources said would address the treatment of detainees and rules of interrogation.
Mr. McCain's spokeswoman, Andrea Jones, would not provide details on Friday, but said, "Senator McCain does plan to introduce legislation next week."
American troops' treatment of detainees has come under fire from Amnesty International, which called Guantanamo Bay the "gulag of our time," and from Democrats like Sen. Richard J. Durbin of Illinois, who compared interrogation techniques there to those under the Nazi and Soviet regimes.
But a Pentagon report two weeks ago found no evidence of inhumane treatment, although it did say that in a couple of cases, detainees faced "abusive" treatment.
Democratic senators plan to offer an amendment calling for a full inquiry by a commission similar to the recent one that investigated intelligence and political failures that contributed to the September 11 terrorist attacks.
Although the Democrats' amendment is unlikely to win broad Republican support, Mr. McCain and Mr. Graham have been working with Armed Services Committee Chairman John W. Warner, Virginia Republican.
On Friday Mr. Warner's spokesman, John Ullyot, could not say whether Mr. Warner would end up supporting the Republicans' amendments.
As chairman, Mr. Warner is shepherding through the bill authorizing all defense expenses, and his reluctance to take a position might stem from the Bush administration's threat Thursday to veto a final House-Senate compromise bill if it includes amendments restricting his right to determine detainee policy.
"The administration strongly opposes such amendments, which would interfere with the protection of Americans from terrorism by diverting resources from the war to answer unnecessary or duplicative inquiry or by restricting the president's ability to conduct the war effectively under existing law," the administration said.