WASHINGTON – Senators trying to broker a compromise on judicial filibusters said yesterday an agreement was possible ahead of a critical vote this week set by majority Republicans to break the logjam on President Bush’s nominees.

Two senators leading talks among the dozen or so lawmakers who could force a deal spoke of the chance of averting a showdown, with a meeting set for today.

But Senators McCain, a Republican of Arizona, and Nelson, a Democrat of Nebraska, said an agreement that would protect the rights of the minority party and prevent abuse of the filibuster is proving elusive.

“We’re having difficulty coming up with exact language which would portray that desire. It’s tough,” Mr. McCain told “Fox News Sunday.”

Mr. Nelson, on CNN’s “Late Edition,” added: “It’s very hard to handicap it at this point in time. But we’ll certainly know tomorrow evening” after the meeting. While wishing that group well, leaders from both parties predicted victory should senators end up voting on the change in procedures, which has come to be known as the “nuclear option.”

“We need to withdraw from the precipice and forge a bipartisan compromise to resolve this matter,” Senate Democratic Leader Reid of Nevada said in prepared remarks yesterday to graduates of the George Washington law school, his alma mater.

“If a compromise cannot be reached, Democrats and responsible Republicans will cast a historic vote for the Constitution and against the nuclear option,” Mr. Reid said.

Senator McConnell, the Republicans’ vote-counter, said Majority Leader Frist, a Republican of Tennessee, had enough votes to stop a filibuster of the nomination of Texas Supreme Court Justice Priscilla Owen.

“If Senator Frist has to exercise [that] option, I believe we’ll have the votes,” Mr. McConnell, a Republican of Kentucky, said on CBS’s “Face the Nation.”

In the shadow of the next Supreme Court vacancy, the debate over Mr. Bush’s judicial nominees has become a fight over the filibuster, a Senate tradition that allows members to hold up legislative business with unlimited talk. Bitterness has festered for years over what both sides say is abuse by the other of that parliamentary tool.

Mr. Frist, another presidential hopeful for 2008, has given Democrats an ultimatum: Stand aside and allow an up-or-down vote on Mr. Bush’s nominees, or prepare for an end to filibusters on judicial nominees. Mr. Frist’s timetable calls for the critical votes to be cast Tuesday and Wednesday. Democrats have refused to comply, insisting that the filibuster be preserved as a check on the rights of the Senate minority.

Senate Republicans gained four seats in the November elections, bringing the vote split to 55 Republicans, 44 Democrats, and one independent. Under parliamentary procedures, 60 votes are needed to end a filibuster and go to a vote. Six senators from each party are needed to force a deal whereby future judicial nominees are not blocked and current filibuster procedures are unchanged.

Mr. McCain said more than 12 senators are interested in participating in a compromise. He said a deal would not block votes on any nominees, but would preserve for the minority party the tools to kill some nominations.

“There would be a commitment to let most of them go” to a vote, Mr. McCain said. “It’s very possible that there would be a vote on all of them, it’s also possible that one or more of them would not reach the Senate floor because of other difficulties that their nomination faces.”