A bipartisan group of eight senators Friday offered a proposal to change some of the chamber’s rules in order to make it more productive and avert Democratic leaders’ threat to overhaul the filibuster.

“We are part of a group of eight senators that have been working now for about a month to come up with a proposal for the leaders and for our conferences that will hopefully overcome the gridlock that has so permeated the U.S. Senate,” said Sen. Carl Levin, D-Mich., at a news conference unveiling the package.

Others in the group include Sens. John McCain, R-Ariz., Charles E. Schumer, D-N.Y., Lamar Alexander, R-Tenn., Benjamin L. Cardin, D-Md., Jon Kyl, R-Ariz., Mark Pryor, D-Ark., and John Barrasso, R-Wyo.

McCain said that he believes that allowing Democrats to alter Senate rules to a simply majority vote — dubbed the “nuclear option” by opponents — would change the Senate for the worse, weakening the minority and diminishing the chamber’s character.

The move “would be, in my view, a disaster and leading to the destruction of the unique aspect of the United States Senate as envisioned by our founding fathers,” McCain said.

Levin agreed that using the nuclear option would set a bad precedent. Proponents of the move, including Sen. Jeff Merkley, D-Ore., Tom Udall, D-N.M., call it the constitutional option.

Senate Majority Leader Harry Reid, D-Nev., and Minority Leader Mitch McConnell, R-Ky., are expected to use the proposal as a template to derive a final package.

The proposal would be put in place as a “standing order,” which requires 60 votes to pass and would sunset at the end of the two-year Congress.

The package would provide two additional alternatives for the majority leader to consider legislation. Currently, any senator can filibuster the so-called motion to proceed, which requires 60 votes to overcome and begin debate.

One option, in lieu of filibustering the motion to proceed, would guarantee Senate consideration of four amendments, two by the majority and two by the minority.

“The key here is what we are giving to the majority leader: the discretion to move to a bill,” Levin said. That would “address the worst problem around here, which is getting to a bill; spending a week with dead time on the Senate floor, while there is a ‘filibuster’ going on on the motion to proceed. That is what we give the majority leader the option to end provided — and this is the trade off — the minority is guaranteed two amendments as well as the majority is guaranteed two amendments.”

Democrats have argued that Republicans have abused the filibuster rule, while Republicans counter that they are left little recourse since Democratic leaders are quick to fill the amendment tree and deny them the right to offer amendments to improve legislation.

The second option would reduce the time it would take cloture to ripen to two hours. Currently, once cloture is filed to cut off debate, the Senate must wait an intervening day before taking a vote. This period would be shortened to two hours on a motion to proceed where both the majority and minority leaders and at least five additional senators from each party sign the cloture motion. If cloture is invoked there would be no post-cloture debate, which can be as long as 30 hours.

The package would also expedite motions to go to conference with the House, with cloture motions ripening after two hours and no post-cloture debate.

On nominations, the proposal would designate 531 nominations for expedited process, leaving 448 to go through the traditional committee process review — unless a senator objects to a nominee.

A cloture motion would ripen after two hours, with no post-cloture debate, under the package if invoked. This change would not apply to prospective members of the Cabinet, officers, officers of Cabinet-level agencies or Article III judges. It would apply to district court judges.

“A major issue that the majority leader has had to face is the filibusters on district court judges,” Levin said. “Effectively, we would say that the post-cloture part of that, which is so troubling — 30 hours of debate after someone has been given 60 votes — that that 30-hour period would be reduced to a two-hour period.”

The package would also call on the enforcement of current rules that the group of senators say are not enforced.

For example, under current rules if no one seeks recognition and the Senate is not in a quorum call, the presiding officer can call for a vote on a measure.

“Under the current rules, which have not been enforced . . . there is precedent in the Senate that if there is no one seeking to debate then the chair may call the question, by the way that is either pre-cloture or post-cloture,” Levin said.

“We are “urging our leaders . . . to alert folks that we are going to apply the current rules,” Levin continued. “We think this is overcome some these filibusters which have so far been able to succeed without anybody talking.”

But Merkley said that in practice those current rules do not require a senator to continually be talking during a filibuster.

“Because the rules allow anyone to call a quorum call and because they can do multiple quorum calls no one has to stay on the floor and talk,” Merkley said.

He also said the proposal doesn’t address the practice of secretly blocking legislation. Currently a senator can simply threaten to filibuster without actually having to go to the floor to make a case.

Merkley said that discussions are expected to continue ahead of a decision by Senate leaders before Jan. 3, when the next Congress begins.

“There is going to be more conversation within the caucus, which Majority Leader Reid has promised, so that we can get everybody’s questions answered with the expectation that he will be able to put together a final package and have 51 senators standing by,” Merkley said.