The Republican push to use a resolution designed to maintain spending levels as a vehicle for making big cuts will drive next week’s budget debate into uncharted territory, and leaders in both parties are unsure about how it will unfold.

“Virtually everything about this [continuing resolution] is unprecedented,” one Republican aide said. “Never before has a CR been used to reduce spending so dramatically, and never before has one been considered under anything approaching an open process.”

House Republican and Democratic leaders are bracing for a prolonged floor fight that will test both leadership teams’ ability to coordinate their rank and file. While conservative Republicans have already made clear they do not think the continuing resolution’s cuts are deep enough, conservative Democrats have made clear they may back GOP reductions in spending despite the objections of Democratic leaders.

Given the political climate surrounding spending and the deficit, undertaking an open amendment process would be hard enough. But with the CR not expected to be introduced until Thursday, Democrats and Republicans remain in a legislative limbo of sorts since both sides’ strategies will be based on how appropriators end up writing the bill.

On top of that, leaders will be dealing with a large and somewhat unpredictable freshman class. “A huge number of Members have never participated in an open debate on the House floor,” the GOP aide said. “Next week’s debate will be challenging.”

Realizing these difficulties, Republican leaders are taking steps to minimize complications.

According to GOP leadership aides, Majority Leader Eric Cantor (Va.), Majority Whip Kevin McCarthy (Calif.) and Rules Chairman David Dreier (Calif.) have sketched out a process for four days of debate on the CR, beginning Monday. From Tuesday to 3 p.m. Thursday, lawmakers are likely to have dozens of floor votes as they slowly work through scores of GOP and Democratic amendments.

Cantor and other leaders have begun urging their Members to work collaboratively on amendments to avoid duplicative proposals. Leaders have also begun reaching out to the parliamentarian to help ensure amendments are germane to the bill, and freshman proposals are being routed to the House’s legislative counsel to make sure they are written correctly.

Because leadership is unlikely to actively whip on most amendments, McCarthy and other senior lawmakers have begun counseling freshman Members on how to whip their colleagues to build support for their proposals.

But while leaders can take some proactive steps, in the end, aides said, the success of the debate will rest on the ability of leaders to manage competing Member demands, time taken for debate and setting realistic expectations in real time on the floor.

Cantor’s goal is to “foster a process to allow Members to offer cuts … that includes making sure we don’t get bogged down in one issue for a few days,” a GOP leadership aide explained.

Similar challenges face House Democrats, who are still working out a strategy for countering Republicans on the spending bill while also offering their own amendments.

“We need to see [the bill] to make any final strategic decisions,” one Democratic leadership staffer said.

Still, the aide noted that Democrats have been focusing on a unified message on the bill to expose Republicans on the claim that the rule is open and on how across-the-board spending cuts are irresponsible.

“We’ll be pointing out the hypocrisy in areas and the truth about the rule they’ve got to set up,” the aide said. “We’re going to need to tighten our belts, but we want to be strategic about where we make cuts and where we make investments.”

In particular, Democratic leadership is trying to shore up support among conservatives in their ranks who have already signaled a willingness to support the spending bill. To do that, they are hoping to address rank-and-file lawmakers’ concerns at the weekly Caucus meeting today.

Budget ranking member Chris Van Hollen (D-Md.), Stan Collender of Qorvis (who is also a Roll Call contributing writer) and Robert Greenstein of the Center on Budget and Policy Priorities are all slated to speak at House Democrats’ weekly Caucus meeting, according to Democratic aides. Jack Lew, director of the Office of Budget and Management, is also expected to attend, although he is not on the official agenda, aides confirmed.

Democrats have also started to outline a process for Members looking to offer amendments. Lawmakers are being asked to work with the Rules and Appropriations committees on crafting amendments to ensure that they are in order and also so that there aren’t duplicative, according to one senior Democratic aide.

Rep. Gerry Connolly said Democrats are most concerned about broad cuts that don’t distinguish between effective programs and others.

“Obviously Democrat concerns are going to be that important programs not be subject to an across-the-board meat ax,” Connolly said. The Virginia Democrat said he wasn’t sure whether he was going to offer an amendment yet. Connolly said that it’s important to continue to draw blood on Republican hypocrisy over the GOP argument that they are offering an open amendment process.