By Ben Weyl, CQ Staff

If the congressional committees that write tax, budget and appropriations bills are the Big Three money panels, what is the “Joint Select Committee on Deficit Reduction,” created by the debt deal?

It’s a “mega supercommittee,” said Olympia J. Snowe , R-Maine, who said Monday that as a senior member of the Senate Finance Committee she was concerned that the new joint panel would “pre-empt all the other congressional committees.”

“How realistic it is to vest all the authority . . . to a 12-member committee that may not have been involved in these issues?” she asked.

The joint panel established by the debt ceiling compromise ( S 365 ) was a component of previous plans from both parties, and would be charged with recommending specific proposals for deficit reduction, with deeply negative consequences to both parties should its report not be adopted.

Its breadth is wide. The panel would be able to consider all facets of the federal government as it seeks to reduce the deficit by $1.5 trillion over 10 years, and it would be required to vote on its recommendations by Nov. 23. The panel’s proposals would need to receive only a simple majority vote in both chambers.

Rep. Norm Dicks of Washington, the top Democrat on House Appropriations, also voiced concern that the panel would usurp traditional authority. “There’s no question — if they can get a proposal, it will affect a lot of jurisdictions here,” he said. But he noted that the full House and Senate eventually would vote on its proposals.

The panel would be made up of three Democrats and three Republicans from each chamber; they would be appointed by the congressional leaders.

Senate Majority Leader Harry Reid , D-Nev., said Monday that he had talked briefly about the issue with Senate Minority Leader Mitch McConnell , R-Ky. Reid said he would decide his selections over the next two weeks and that he would choose individuals apt to compromise.

“It’s extremely important that I pick people who are willing to make hard choices but are not locked in,” Reid said. “We have to go into this with people with our eyes wide open, willing to make difficult choices — but yet understand the political reality of the world we are in.”

Already a serious dispute exists over whether the committee will include additional revenue in its final proposal, with many Democrats assuming that will be the case, even as House Republicans have been assured that that will not happen.

Reid said he had been told that House Majority Leader Eric Cantor , R-Va., had suggested that revenue might come out of the joint committee. Later Monday, Cantor responded, “I can tell you flat-out, he is wrong.”

Sen. Robert Menendez , D-N.J., announced his opposition to the deal Monday, in part because he is convinced GOP lawmakers will refuse to consider raising taxes.

Democratic supporters of the deal are saying that “the commission can look at revenue,” Menendez said on the Senate floor. “Yes, it can look at revenue. But that commission, which is going to be appointed with an equal number of Republicans and Democrats, pretty much tells you where it’s going to end up.”