Sen. Bernie Sanders’ office believes that his amendment calling for an audit of the Federal Reserve will “probably” require 60 votes in order to pass and get into the broader financial reform bill, whether because of a bipartisan agreement on vote thresholds for amendments or a filibuster from a Senator opposed to the amendment.

Contrary to previous reports, there are only 18 co-sponsors on the amendment, which would empower the Government Accountability Office to perform the audits and allow more transparency on the trillion-dollar deals the Fed has been engaged in with the largest banks in America and the world. There is a separate bill, S.604, the Federal Reserve Sunshine Act of 2009, which takes a similar approach to auditing the Fed and has 33 co-sponsors. But so far on this amendment, we’re at 18:

Sanders, Feingold, DeMint, Leahy, McCain, Wyden, Grassley, Dorgan, Vitter, Boxer, Brownback, Risch, Wicker, Graham, Hatch, Crapo, Bunning, Bennett (UT).

If you add together those Senators who co-sponsored the bill but not the amendment:

Barrasso, Burr, Cardin, Chambliss, Coburn, Cochran, Cornyn, Harkin, Hutchison, Inhofe, Isakson, Landrieu, Lincoln, Murkowski, Thune, Webb.

…you’re at 34 (for some reason Bunning has sponsored the amendment but not the bill). But when asked if there would be a 60-vote threshold for the amendment, Senior Policy Advisor to Sen. Sanders Warren Gunnels responded, “Nothing has been decided, but probably 60.”

The amendment could get its vote as soon as tomorrow. There’s no indication that the White House or the Senate leadership is doing any active whipping against the bill outside of the Wall Street Journal article on Friday which said the Administration wanted it blocked. Putting up a 60-vote threshold, whether through agreement or by one Senator blocking consideration and forcing a cloture vote, would be one way to do that.

It should be noted that in 2009, there was a vote on an amendment to audit the Fed, as well as obtain “information from the Fed about the use of emergency assistance” for the financial industry. It received 59 votes, and 8 of the 39 no votes came from Senators who have co-sponsored either the bill or the amendment (Barrasso, Bennett, Chambliss, Cochran, Hatch, Isakson, Murkowski, Wicker). So theoretically, there are as many as 67 votes for such an amendment, but whether Sanders and his bipartisan coalition will get there remains to be seen.

The 59 Yes votes from April 2, 2009:

Akaka (D-HI), Begich (D-AK), Boxer (D-CA), Brown (D-OH), Brownback (R-KS), Bunning (R-KY), Burr (R-NC), Burris (D-IL), Byrd (D-WV), Cantwell (D-WA), Cardin (D-MD), Casey (D-PA), Coburn (R-OK), Collins (R-ME), Conrad (D-ND), Cornyn (R-TX), Crapo (R-ID), DeMint (R-SC), Dorgan (D-ND), Durbin (D-IL), Ensign (R-NV), Feingold (D-WI), Feinstein (D-CA), Graham (R-SC), Grassley (R-IA), Hagan (D-NC), Harkin (D-IA), Hutchison (R-TX), Inhofe (R-OK), Inouye (D-HI), Kerry (D-MA), Klobuchar (D-MN), Landrieu (D-LA), Leahy (D-VT), Levin (D-MI), Lincoln (D-AR), McCain (R-AZ), McCaskill (D-MO), Merkley (D-OR), Mikulski (D-MD), Murray (D-WA), Nelson (D-FL), Pryor (D-AR), Reid (D-NV), Risch (R-ID), Roberts (R-KS), Rockefeller (D-WV), Sanders (I-VT), Sessions (R-AL), Snowe (R-ME), Specter (D-PA), Stabenow (D-MI), Tester (D-MT), Thune (R-SD), Udall (D-NM), Vitter (R-LA), Webb (D-VA), Whitehouse (D-RI), Wyden (D-OR)

UPDATE: Ryan Grim reports that Sanders has been “trading calls” with Rahm Emanuel about the amendment, and that he’s going up against “all of Wall Street… the Fed, obviously, and unfortunately you seem to be taking on the White House, as well.”

Grim also notes that Scott Brown (R-MA) appears supportive of this measure, along with George LeMieux (R-FL). Last April, Ted Kennedy didn’t vote on the amendment that attracted 59 votes, and Mel Martinez voted no. So we could be up to 69 potential yes votes.