Washington ? Faced with losing his bid to block the USA Patriot Act, Sen. Russell Feingold is preparing a last-ditch strategy to amend the legislation with stronger safeguards against government intrusion and more frequent congressional oversight.

The effort is unlikely to succeed. Virtually every other senator, including the leaders of his party, have pledged to vote for the White House-brokered deal that supporters say makes the most changes possible without jeopardizing passage before the terrorism-fighting law expires March 10.

“The outcome here is absolutely predetermined,” said Majority Leader Bill Frist, R-Tenn., expressing frustration with the Feingold-led delay.

Without any apparent supporters for his filibuster, Feingold, D-Wisc., bowed to Frist’s insistence on holding a procedural test vote today that would clear the way for Senate debate on the legislation. Frist said the Senate would hold its final votes at the end of the month.

During the process, Feingold will try to introduce several amendments that would strengthen protections for civil liberties.