The Pentagon's top uniformed lawyers took issue Thursday with a key part of a White House plan to prosecute terrorism detainees, telling Congress that limiting the suspects' access to evidence could violate treaty obligations.

Their testimony to a House committee marked the latest time that military lawyers have publicly challenged Bush administration proposals to keep some evidence — such as classified information — from accused terrorists. In the past, some military officials have expressed concerns that if the U.S. adopts such standards, captured American troops might be treated the same way.

The lawyers' testimony contrasted with the panel chairman's assertion that the United States must take a harder line when prosecuting terrorists.

Rep. Duncan Hunter, who heads the House Armed Services Committee, said at the hearing that any military commission established to prosecute terrorists must allow the government to protect intelligence sources. In saying so, the California Republican aligned himself with the White House position.

"While we need to provide basic fairness in our prosecutions, we must preserve the ability of our war fighters to operate effectively on the battlefield," Hunter said.

Hunter presented the military lawyers with various scenarios in which it might be necessary to withhold evidence from the accused if it would expose classiay from elections when all members will try to sell themselves as tough on terror.

Bush's announcement was immediately praised by those who said his policies were necessary to win the war on terror.

Senate Majority Leader Bill Frist, R-Tenn., said he wants a vote on the bill by the end of the month and will likely decide Friday how quickly to push the bill to the floor. House Majority Leader John Boehner, R-Ohio, has promised a vote on the administration's measure there during the week of Sept. 18.

But some GOP moderates in the Senate are challenging the proposal. They include three senators with hefty credentials: Sen. John McCain of Arizona, who spent more than five years as a prisoner of war in North Vietnam; Sen. Lindsey Graham of South Carolina, a former military lawyer who still serves in the Air Force Reserves as a reserve judge; and Sen. John Warner of Virginia, chairman of the Armed Services Committee.

A leadership aide said Warner, McCain and Graham were given "24 hours to think their position over," indicating a possibility the bill could be routed around the Armed Services Committee and placed directly on the Senate floor.