The landmark legislation expanded the government's power to use eavesdropping, surveillance, access to financial and computer records and other tools to track terrorist suspects.

When it passed in October 2001, moderates and civil libertarians in Congress agreed to support it only by making many critical provisions temporary. Those provisions will expire, or "sunset," at the end of 2005 unless Congress re-authorizes them.

But Republicans in the Senate in recent days have discussed a proposal, written by Senator Orrin G. Hatch, Republican of Utah, that would repeal the sunset provisions and make the law's new powers permanent, officials said. Republicans may seek to move on the proposal this week by trying to attaching it to another antiterrorism bill that would make it easier for the government to use secret surveillance warrants against "lone wolf" terrorism suspects.

Many Democrats have grown increasingly frustrated by what they see as a lack of information from the Justice Department on how its agents are using their newfound powers, and they say they need more time to determine whether agents are abusing those powers.

The Senate Democratic leader, Tom Daschle of South Dakota, said today that without extensive review, he "would be very strongly opposed to any repeal" of the 2005 time limit. He predicted that Republicans lacked the votes to repeal the limits.

Indeed, Congressional officials and political observers said the debate might force lawmakers to take stock of how far they were willing to sacrifice civil liberties in the name of fighting terrorism.

Beryl Howell, a former Democratic aide in the Senate who worked extensively on the 2001 legislation, said that by forcing the issue, Mr. Hatch "is throwing down the gauntlet to people who think the U.S.A. Patriot Act went too far and who want to cut back its powers."

Justice Department officials in interviews today credited the Patriot Act with allowing the F.B.I. to move with greater speed and flexibility to disrupt terrorist operations before they occur, and they say they wanted to see the 2005 time limit on the legislation lifted.

"The Patriot Act has been an extremely useful tool, a demonstrated success, and we don't want that to expire on us," a senior department official said on condition of anonymity.

Another senior official who also demanded anonymity said the department had held discussions with Congressional Republicans about how that might best be accomplished. "Our involvement has really been just keeping an open ear to the issue as it's proceeding, not to really guide the debate," the official said.

With the act's provisions not set to expire for more than two and a half years, officials expected that the debate over its future would be many months away. But political jockeying over separate bipartisan legislation sponsored by Senators Jon Kyl, Republican of Arizona, and Charles E. Schumer, Democrat of New York, appears to have given Senator Hatch the chance to move on the issue much earlier than expected.

The Kyl-Schumer measure would eliminate the need for federal agents seeking secret surveillance warrants to show that a suspect is affiliated with a foreign power or agent, like a terrorist group.

Advocates say the measure would make it easier for agents to go after "lone wolf" terrorists who are not connected to a foreign group and might have allowed the F.B.I. to get a warrant against Zacarias Moussaoui, known as the 20th hijacker, before the Sept. 11 attacks.

The proposal was approved unanimously by the Senate Judiciary Committee. But Republicans are upset because several Democrats say that when the measure reaches the Senate floor for a full vote, perhaps this week or later in the month, they plan to offer amendments that would impose tougher restrictions on the use of secret warrants.

Among other proposals, Senator Russell D. Feingold, Democrat of Wisconsin, wants to add amendments that would require the Justice Department to give detailed information about how the secret warrants are being used and that could give defense lawyers access to some information generated by the warrants in criminal cases.

Republicans are countering with amendments of their own, including the idea of making the Patriot Act permanent.

Aides to Senator Hatch would not discuss his views on repealing the time limits in the law.

But an aide who demanded anonymity said of the "lone wolf" bill: "We support this bill as it is and that's how we want to see it passed. If the Democrats want to amend the bill, then we will offer an equal number of amendments to improve the bill as well. We hope the Democrats will stop holding this bill up."

Members of the Judiciary Committee, which Mr. Hatch leads, have been working in recent days to reach an agreement over the amendments that will be considered, officials said. But so far neither side appears willing to back down.

Copyright 2003 The New York Times Company