Sen. Bernie Sanders (I-Vt.) touted what he said was growing bipartisan support over the weekend for a bid to audit the Federal Reserve.

Sanders released a draft amendment to Democrats' Wall Street reform bill cosponsored by 15 senators from both parties that would require an audit of the Fed.

The measure mirrors a similar bid pushed by Rep. Ron Paul (R-Texas) in the House, for which, Sanders said on Saturday, there was growing support.

To that end, Sanders's office released a letter from AFL-CIO legislative director bill Samuel supporting the amendment, and another letter from SEIU President Andy Stern, which was cosigned by a number of other academics, labor leaders, and heads of watchdog groups.

The measure has already been backed by a number of conservative groups, from Citizens Against Government Waste to Freedomworks.

The Senate will begin the process of amending the Wall Street reform bill next week, with the first votes scheduled for Tuesday. In addition to the audit amendment, senators will vote on measures to limit the size of big banks, ensure fewer bailouts, and possible reinstate a historic separation between banks' commercial and investment operations.

The Sanders amendment listed the following cosponsors: Sens. Russ Feingold (D-Wis.), Jim DeMint (R-S.C.), Patrick Leahy (D-Vt.), John McCain (R-Ariz.), Ron Wyden (D-Ore.), Chuck Grassley (R-Iowa), Byron Dorgan (D-N.D.), David Vitter (R-La.), Barbara Boxer (D-Calif.), Sam Brownback (R-Kansas), Jim Risch (R-Idaho), Roger Wicker (R-Miss.), Lindsey Graham (R-S.C.), Orrin Hatch (R-Utah), and Mike Crapo (R-Idaho).