WASHINGTON —  A long-threatened showdown over changing Senate rules to stop Democratic filibusters of President Bush's judicial nominations could come as early as next week, Senate Majority Leader Bill Frist (search) said Tuesday.

Frist, in his weekly news conference with reporters, said he hopes the Senate finishes a highway bill and an emergency spending package to fund military operations overseas this week.

"And then we need to turn to 100 United States senators and move to the issue surrounding judges," he said.

Senate Democratic leader Harry Reid of Nevada said he's ready and expects to win.

"I want to be clear: We are prepared for a vote on the nuclear option," Reid said in a letter to Frist, referring to the GOP threat to change the filibuster rules. "Democrats will join responsible Republicans in a vote to uphold the constitutional principle of checks and balances."

Democrats have blocked 10 of Bush's appellate court choices through filibuster threats, requiring those nominees to get 60 votes in the 100-member Senate instead of the simple majority needed for Senate confirmation. None of the 10 could clear that threshold.

Democrats have again threatened to block the seven Bush renominated this year, as well as future nominees they consider outside the mainstream of legal thinking. Frist and Republicans in turn have threatened to use their majority to change Senate rules so that filibusters would not be permitted for judicial confirmations.

Conservatives have been pushing Frist to get the rules changed in expectation of a Supreme Court vacancy during Bush's second term.

Frist suggested that the nomination of former Interior Department lawyer William Myers (search) for the 9th U.S. Circuit Court of Appeals in San Francisco could be the first test vote.

Myers, blocked by Democrats last year, was the first of the seven judicial nominees to get approval from the Judiciary Committee this year and has been waiting on a floor vote.

Senate Judiciary chairman Arlen Specter, R-Pa., suggested Monday the Senate should take up nominees in the order that his committee moves them for approval. "I think it's time to do that," Frist said, referring to Specter's remarks.

While Myers is opposed by environmentalists because of his record as the Interior Department's top lawyer during Bush's first term and his representation of ranching and mining interest as a private attorney, Republicans believe he could get more votes from Democrats than the other filibustered nominees.

That means if Democrats don't filibuster Myers again, former Senate lawyer Thomas Griffith's (search) nomination to the U.S. Circuit Court of Appeals for the District of Columbia would be next, followed by Texas judge Priscilla Owen's (search) nomination to the 5th U.S. Circuit Court of Appeals and California judge Janice Rogers Brown's (search) nomination to the D.C. circuit, according to the Senate calendar.

Reid, D-Nev., offered Monday to help Frist confirm Griffith first, who was never given a confirmation vote from the GOP-controlled Judiciary Committee. Frist rejected the offer, saying all Bush nominees deserve the opportunity for a confirmation vote.

Reid, in his letter, reiterated his offer to help confirm Griffith as a bonus to his previous proposal. He suggested allowing confirmation for three nominees -- Michigan nominees Richard Griffin, David McKeague and Susan Neilson -- plus one of the four most controversial nominees: Owen, Brown, Myers and William Pryor.

The others would be dropped.

He also suggested that Frist push a previous plan to reduce the number of senators needed to break a filibuster. Although that plan would required 67 senators' agreement, "I don't think that is an insurmountable obstacle for some improvements in the process by which the Senate considers judicial nominees," Reid's letter said.

He again rejected Frist's compromise offer to allow up to 100 hours of debate for each appeals court and Supreme Court nominee, followed by a guaranteed confirmation vote requiring only a simple majority.

"Your proposal simply places a delayed fuse on the nuclear option," Reid said in his letter to Frist.