Party leaders are giving the new super committee some space to build a bipartisan deficit plan, but they are staying close enough to the process to continue as the unseen hands behind the scenes.

Indeed, the new Joint Committee on Deficit Reduction is unlikely to reach a “grand bargain” without the leaders’ signoff.

While there is speculation about the 12 members of the panel and whether one or two are susceptible to being wooed to the other side, that’s just not going to happen, several aides in both parties predicted. None of the appointees are obvious candidates for such an apostasy, and they were picked in part because of their loyalty.

Any bill that doesn’t ultimately have the approval of Speaker John Boehner (R-Ohio), Senate Majority Leader Harry Reid (D-Nev.) and Senate Minority Leader Mitch McConnell (R-Ky.), as well as the president, isn’t going to go anywhere, fast-track rules or not. (Given the nature of the House, Minority Leader Nancy Pelosi’s backing isn’t necessarily as critical.)

The leaders “want and will have final say on anything that goes on in that room,” one Democratic aide close to the committee said. “There will be freedom to operate, but there will not be a deal struck without all of those guys on board.”

And any final vote on a package will either be broadly bipartisan or divided on party lines. “This isn’t going to be 7 to 5,” the Democratic aide added. “It’s going to be 10 to 2 or 6 to 6.”

Early indications show that the panel will at least make a serious attempt to produce a bipartisan product.

With a few exceptions, each party’s leadership — and the committee members themselves — have ratcheted down the partisan rhetoric in advance of the committee’s first meeting, scheduled for Thursday.

Rep. Chris Van Hollen (D-Md.), who is on the super committee, said he has been pleased with the statements from both sides. “All I know is that, so far, the leaders have been supportive of the effort,” he said in a phone interview last week. “I don’t want to prejudge anything, but so far, I think there’s been bipartisan support for giving this committee a chance and an opportunity for us to come up with a plan. Hopefully, that will remain the case.”

One Senate GOP aide predicted that the committee would ultimately cobble together something, even if it only makes a slight dent in the deficit.

“Reid, McConnell and Boehner want to get something done,” the aide said. “There’s not going to be sequestration.” Sequestration is the term for the $1.2 trillion in automatic spending cuts that would take effect Jan. 1, 2013, if the committee fails to act.

Another Senate Democratic aide said that both Reid and McConnell appear to have a sense of ownership over the committee — which was Reid’s idea but  was quickly embraced by McConnell — and both have an incentive for it to produce something.

The second Democratic aide said that McConnell has been careful to note that the committee is not simply another “commission,” because it has been designed to produce a result and will get automatic votes in both chambers.

This aide added, “individuals that got selected to the committee wanted to be on it and lobbied to be on it. They didn’t lobby to be on it so they could be a party to a failure.”

Some of the picks, including Sen. Pat Toomey (R-Pa.), former president of the conservative Club for Growth, have shown a somewhat surprising willingness to eliminate tax breaks, such as one for ethanol makers — a key demand of Democrats.

“If you’re Pat Toomey and you’re from a purple state, this is an opportunity for you to be a statesman,” one Democratic aide said.

Boehner spokesman Michael Steel also said the Speaker wants a deal.

“Starting to get our deficit and debt under control to help ease the uncertainty that is making it harder to create American jobs must be a priority for every Member of Congress,” Steel said in an email. “Rep. [Jeb] Hensarling [R-Texas] — a member of the House Republican Leadership — will take the lead as co-chairman of the Joint Committee, and our entire Leadership team is ready and willing to do everything they can to help.” Sen. Patty Murray (D-Wash.) is the other co-chairman.

Aides in both parties also noted positively the fact that the committee quickly agreed on a staff director last week — longtime Republican Finance Committee aide Mark Prater — as well as an initial schedule that includes a hearing on Sept. 13. Of course, Prater’s selection had approval from the leaders, who were also instrumental in selecting him, sources said.

And while panel members held partisan strategy sessions last week in advance of the full committee convening, bipartisan discussions have already begun. Still, aides caution that the ideological divide between the parties that scuttled earlier efforts hasn’t dissipated.

Democrats say House Majority Leader Eric Cantor’s Aug. 17 call for the committee to take revenue off the table didn’t help. At the time, Reid countered that without revenue, there won’t be a bill. Boehner and the Virginia Republican penned an op-ed in USA Today last week saying they believe the panel can reach a deal without tax increases. However, one GOP aide said that Cantor’s main focus in the coming months would likely be his jobs agenda.

To some extent, an air war between the two parties over what to do is inevitable. But the question will be whether the committee can succeed on a separate, substantive track.

There has been some optimism that a tax reform package that lowers rates and generates revenue could be the key ingredient that cements a deal, but aides in both parties are skeptical. That’s in part because the complex job of estimating the costs and savings of massive changes in the tax code would be a lengthy process — even if both sides were to agree on what those changes should look like.

Without the revenue from tax reform or eliminating corporate tax breaks, Democrats are unlikely to agree to deep cuts in entitlement benefits.

Van Hollen said his Democratic colleagues are committed to reaching a sweeping deal that seeks to make $3 trillion in deficit reduction. He called for spending on infrastructure projects, alongside cuts elsewhere. He added that tax reform “should be part of the mix.”

Despite Van Hollen outlining a few goals for the super committee, Members have largely stayed away from setting out any demands. House Republican aides maintain that their representatives at the table are skilled negotiators and that House GOP leaders want them to reach an agreement. Indeed, one GOP aide noted, “If you look at who we picked to have on this committee, we picked some pretty serious people. I really think the expectation from our side is that we get some stuff done.”

Besides Hensarling, Van Hollen, Toomey and Murray, other members of the panel are Sens. Jon Kyl (R-Ariz.), Rob Portman (R-Ohio), Max Baucus (D-Mont.) and John Kerry (D-Mass.) and Reps. Dave Camp (R-Mich.), Fred Upton (R-Mich.), Xavier Becerra (D-Calif.) and James Clyburn (D-S.C.).