Republicans are threatening to bring the Senate to a "screeching halt" if Majority Leader Harry Reid, D-Nev., follows through with plans to curtail the use of the filibuster the GOP has used to block non-judicial presidential nominations.

In a chamber where the rules require even the simplest business, such as committee hearings, to receive the "unanimous consent" of all 100 senators, Republicans warn that Reid's threat to invoke the so-called "nuclear option" would inflame partisanship and exacerbate gridlock beyond anything seen in the past decade.

It remains unclear if Republicans would maintain the effort, which would require hourly objections to Democratic unanimous consent requests, but a strategy of harsh retaliation appears to be gaining favor.

"I think it would bring the chamber to a screeching halt," Sen. Richard Burr, R-N.C., said.

"My guess is we would use the tools at our disposal to make [Democrats] regret this decision, if they make it," added a second Republican senator, who spoke on condition of anonymity in order to discuss internal caucus sentiment.

Reid was scheduled to meet Thursday behind closed doors with his caucus to discuss the potential rules change. The move has been resisted by veteran Democrats, but is being pushed by members elected more recently. Democratic sources have confirmed that Reid could move ahead with the process to implement the "nuclear option" as early as next week.

Sixty votes are required to overcome a filibuster, and under current rules, most floor votes are subject to this threshold. Under the rule change, only a simple majority of 51 votes would be needed.

The majority leader suggested during his Thursday morning floor remarks that he was headed toward protecting non-judicial executive branch nominees, including cabinet picks, from the filibuster, which he blamed on Senate Minority Leader Mitch McConnell, R-Ky., and what the Democrat said was McConnell's violation of an agreement struck earlier this year that would limit GOP filibusters of nominees. McConnell has lobbed similar charge at Reid.

"The Republican leader has failed to live up to his commitments," Reid said. "I refuse to unilaterally surrender my right to respond to this breach of faith."

Reid is under pressure from the White House and liberal interest groups and activists to change his chamber's parliamentary rules to make it easier to confirm President Obama's nominees, although the change would not apply to judicial nominees. The plan is also controversial because Reid's plan calls for changing the rules with only 51 votes, which means Democrats could change them without Republican consent. Through a complicated maneuver, the Nevadan would skirt the 67-vote threshold for changing Senate rules.

Republican sources said that McConnell and his conference had yet to settle on a specific plan of attack if Democrats are able to muster enough votes to approve the rules change. But Republican sources with Senate ties said a clue to how the GOP might respond could be found in how much attention McConnell has paid to this issue over the past several weeks.

McConnell, who is up for re-election in 2014 and is angling to become the Senate majority leader, has probably used his floor time and weekly press conferences to discuss this issue more than any other. Should Republicans respond aggressively, it could include objections to dispensing with the reading of a bill — lengthier bills could take days to read — and objecting to conducting floor remarks without a quorum of senators present.

Over the course of his career, Reid has been a zealous defender of the filibuster, and has been loathe to diminish its reach, agreeing with Republicans that curtailing it for some votes could lead down a slippery slope to similar rule changes that could strip the minority party of crucial influence. That is why some Republicans believe Reid will ultimately back away from this threat.

Meanwhile, GOP sources believe that Reid and the Democrats are gambling that Republicans would ultimately grow tired of jamming up the chamber, and that Senate business would go back to normal after awhile. But these sources warn that while some GOP senators might lose interest, others wouldn't, and all it takes is one angry member to freeze the chamber.

Sen. Tom Coburn, R-Okla., said one of two things will happen.

"You could do nothing or you could make everything not work," he said. "A decision will have to be made on that."