The USA Patriot Act is headed toward renewal with most of its onerous individual rights violations intact and broad Senate support for a White House-brokered compromise that adds a few token new civil liberties protections to the terror-fighting law.

“The outcome here is absolutely predetermined,” Senate Majority Leader Bill Frist, R-Tenn., said late Wednesday. “It’s going to pass with overwhelming support.”

With even senior Democrats lining up behind the measure, its lone opponent, Sen. Russell Feingold, was preparing amendments he said would strengthen its curbs on government power. Congress is racing to renew 16 provisions of the law that are set to expire March 10.

During the process, Feingold, D-Wis., was trying to attach an amendment to set a four-year expiration date on the use of National Security Letters _ demands for records issued by administrators _ under the Patriot Act, according to a spokesman.

Another amendment would require the government to notify the subject of a secret search within seven days or obtain court permission to maintain the secrecy for a longer period, rather than the 30-day requirement in the legislation being considered.

While the filibuster was a lone endeavor, Feingold had plenty of company in wanting the 2001 anti-terrorism law to include more curbs on the government’s power to investigate people.

The bill’s sponsor, Sen. Arlen Specter, R-Pa., said a full makeover was unlikely to pass Congress before March 10.

“Sometimes cosmetics will make a beauty out of a beast and provide enough cover for senators to change their vote,” Specter told reporters Wednesday.

Indeed, virtually every senator who had stood with Feingold last year to kill a House-Senate agreement abandoned the effort this month after two of them, both Republicans, struck a deal with the White House to add more privacy protections.

Now, the legislation’s supporters include the chamber’s most senior Democrats, and the 60 votes required to overcome Feingold’s filibuster.

Frist said the Senate planned procedural votes on the matter beginning Thursday and stretching beyond congressional recess next week. Final votes were expected to resume at the end of the month.

Sen. John Sununu, R-N.H., shared Feingold’s concern but said his talks with the White House produced improvements to the law’s civil liberties protections.

“In an effort like this, no party ever gets everything that they want,” Sununu said.

Under the deal, recipients of court-approved subpoenas for information in terrorist investigations would have the right to challenge a requirement that they refrain from telling anyone.

Another new protection would remove a requirement that an individual provide the FBI with the name of an attorney consulted about a National Security Letter.

A third improvement, supporters say, makes clear that most libraries are not subject to National Security Letter demands for information about suspected terrorists.

But Feingold said the new deal makes only one modest improvement over the defeated House-Senate compromise and current law: It makes clear that there would be judicial review of “gag orders” issued with court-ordered subpoenas for information, but sets several conditions. Under one, the review can only take place after a year and requires the recipient of the order to prove the government has acted in bad faith, Feingold said.

“That is a virtually impossible standard to meet,” he said.