Senate Republicans will begin debate on the judicial nomination of Priscilla Owen (search) on Wednesday morning, hoping to break a Democratic block on the candidates and holding off until next week any efforts to abolish judicial filibusters.

Democrats call the Republican plan to end filibusters on nominees a "nuclear option (search)" and have threatened to stall work in the chamber if Republicans manage to do away with Democratic blocks. Sixty Senate votes are needed to overcome a filibuster, the endless debate aimed at preventing a vote. Only 51 votes are needed to approve a candidate if he or she is given a regular vote.

"The filibuster is the last check against abuse of power in Washington," said Senate Democratic leader Harry Reid (search) said Tuesday. "The goal of the Republican leadership in this body and their allies in the White House is to pave the way for the future that the Senate would basically be eliminated from the confirmation process. They don't want consensus, they want confirmation."

Republicans, however, say removing the procedural barrier is the only way to get a vote on stalled judicial nominees.

"I suggest to you the only thing nuclear about changing rules is the threat of Harry Reid, the Democratic leader, to shut down the U.S. Senate unless they get their way," said Sen. John Cornyn (search), R-Texas, who served on the Texas Supreme Court with Owen.

Republican sources told FOX News that the GOP leadership will allow debate this week on the nominees, and early next week will call for a vote to end debate on Owen's nomination to the 5th Circuit Court of Appeals. If they are unable to get through the 60-vote threshold to end debate, they will then vote to abolish filibusters on judicial nominees. That vote would require a simple majority to succeed and set a new precedent.

"Each of these nominees coming from the president of the United States, for circuit courts and for the Supreme Court, the highest courts in the land, deserve a fair up-or-down vote. Up-or-down vote, confirm or reject, yes or no," Frist said.

Owen and Janice Rogers Brown (search), a California Supreme Court justice nominated to the Circuit Court of Appeals for the District of Columbia, did the rounds on Tuesday, appearing on Capitol Hill where they met with senators, and visiting the White House where President Bush greeted his female nominees. After weeks of silence that irritated Senate Republicans, the White House demanded floor votes for all seven of Bush's blocked nominees.

"The Constitution says advise and consent, not advise and block," said Press Secretary Scott McClellan.

Republicans also accused Democrats of rewriting the Constitution by demanding 60 votes for certain Bush nominees.

"The Constitution is very clear when a supermajority is required for any action, and advise and consent does not say a supermajority is required," said Sen. Kay Bailey Hutchison of Texas.

But Reid said that if Republicans try to remove his party's ability to block the president's candidates, Democrats will "no longer have to be deferential" to Republicans, meaning they will make good on an earlier threat to grind the Senate to a halt.

Sen. Trent Lott (search), R-Miss., whose state is under the jurisdiction of the 5th Circuit Court, said Reid's threats won't change much from the current state of affairs.

"What's new about that?" he asked. "Look, we're not making a whole lot of progress now. Everything this year has been slow waltz. ... We have been in session four and a half months, we've produced four bills, how much slower can you get?"

On Monday, Reid ended negotiations with Frist to avoid the nuclear option. On Tuesday, Democratic Sen. Ben Nelson of Nebraska and Republican Sen. John McCain (search) of Arizona continued secretive talks with six Democrats and six Republicans on a compromise that would preserve the use of the filibuster and guarantee confirmation votes on up to five of the seven blocked Bush judicial nominees.

Top Nelson aides tell FOX News that Nelson and five Democrats are willing to allow floor votes on Owen and Brown, but only if Republicans agree to keep the filibuster and abandon some of the president's lesser-known judicial nominees.

Reid deferred to Nelson, but defined his limits.

"There can be nothing done or any side arrangements — call it whatever you want — if it takes away the ability to filibuster and the nuclear option is still on the table, we've got to have the nuclear option off the table for this Congress," he said.

Late Tuesday, no compromise had been reached.

"We had a good healthy discussion but no breakthrough. I really think people on both sides don't want this to happen," said Sen. Joe Lieberman, D-Conn.

FOX News' Major Garrett, Julie Asher and Molly Hooper contributed to this report.