WASHINGTON — Two months after vowing to roll back broad new wiretapping powers won by the Bush administration, congressional Democrats appear ready to make concessions that could extend some of the key powers granted to the National Security Agency.

Bush administration officials say they are confident they will win approval of the broadened wiretapping authority that they secured temporarily in August as Congress rushed toward recess, and some Democratic officials admit that they may not come up with the votes to rein in the administration.

A Democratic bill to be proposed Tuesday in the House would maintain for several years the type of broad, blanket authority for NSA wiretapping that the administration secured in August for just six months. But in an acknowledgment of civil liberties concerns, the measure would also require a more active role by the special foreign intelligence court that oversees the NSA's interception of foreign-based communications.

A competing proposal in the Senate, still being drafted, may be even closer in line with the administration's demands, with the possibility of including retroactive immunity for telecommunications companies that took part in the NSA's once-secret program to wiretap without court warrants.

The August bill, known as the Protect America Act, was approved by Congress in the final hours before its summer recess after heated warnings from the administration that legal loopholes in wiretapping coverage had left the country vulnerable to another terrorist attack. The legislation significantly reduced the role of the foreign intelligence court and broadened the NSA's ability to listen in on foreign-based communications without a court warrant.

"We want the statute made permanent," Dean Boyd, a spokesman for the Justice Department, said Monday. "We view this as a healthy debate. We also view it as an opportunity to inform Congress and the public that we can use these authorities responsibly. We're going to go forward and look at any proposals that come forth, but we'll look at them very carefully to make sure they don't have any consequences that hamper our abilities to protect the country."