Sen. John Ensign (R-Nev.) on Monday turned down an offer to break the logjam on a bill requiring Senators to file their campaign finance reports electronically. Those reports are currently filed on paper only and must be scanned into computers.

In a letter Monday to Senate Rules and Administration Chairwoman Dianne Feinstein (D-Calif.), Ensign rejected her entreaty to drop his insistence on offering a controversial amendment that would require nonprofits that file Senate ethics complaints to disclose their donors.

“In the Senate, complaints do not have to be sworn, signed, or even identified, and they can be submitted by a person or an unnamed group and no one will ever know,” Ensign wrote in the letter. “They can be on a beverage napkin or written in crayon. In contrast, the House … has very formal, rigorous requirements for filing complaints.”

Ensign was responding to a Nov. 14 letter in which Feinstein said the controversy over his amendment was preventing a bipartisan measure from passing the chamber. She added that the proposal would affect current tax law and is viewed as “obstructionist” by affected nonprofits. She offered to hold a hearing in the Rules Committee on the issue instead.

Ensign accepted the offer of a hearing, saying he would “be more than happy to testify … on the need to increase transparency of the ethics complaint process.”

Feinstein’s office reacted negatively to Ensign’s letter Monday.

The electronic filing bill “has the broad bipartisan support of 41 Senators, including 16 Republicans,” Howard Gantman, the Rules panel’s staff director, said. “It is a common-sense bill that would dramatically increase the transparency of campaign fundraising practices in Senate elections. Now is not the time to try to encumber the bill with a potential poison pill that has triggered broad ideologically diverse public opposition.”