WASHINGTON — US Senate Democrats struggled without success Monday to rally the 60 votes needed to ensure passage of a sweeping Wall Street overhaul bill after the death of Democratic Senator Robert Byrd.

Democratic Senator Russell Feingold dashed hopes he would abandon his opposition to the bill after Byrd's passing, saying in a statement that the measure did not go far enough to forestall a repeat of the 2008 meltdown.

“As I have indicated for some time now, my test for the financial regulatory reform bill is whether it will prevent another crisis,” Mr. Feingold said in a statement. “The conference committee’s proposal fails that test and for that reason I will not vote to advance it.

During debate on the bill, I supported several efforts to break up ‘too big to fail’ Wall Street banks and restore the proven safeguards established after the Great Depression separating Main Street banks from big Wall Street firms, among other issues. Unfortunately, these crucial reforms were rejected. While there are some positive provisions in the final measure, the lack of strong reforms is clear confirmation that Wall Street lobbyists and their allies in Washington continue to wield significant influence on the process.”

The New York Times notes that "Feingold’s continuing opposition and the death on Monday of Senator Robert C. Byrd, Democrat of West Virginia who had supported the bill, mean that Democrats face an even tougher than expected challenge in winning approval of the regulatory overhaul."

Mr. Feingold cited five amendments to the Senate version of the legislation that he supported and said would have made the bill stronger. None of them were included in the final version of the legislation. The amendments included a proposal sponsored by Ms. Cantwell to restore the firewall between commercial banking and investment banking in the Glass-Steagall Act, which was approved in response to the Great Depression and repealed in 1999. Mr. Feingold voted against the repeal.

Mr. Feingold also cited an amendment by Senators Sherrod Brown, Democrat of Ohio, and Edward E. Kaufmann, Democrat of Delaware, that would break up some of the nation’s biggest banks and an amendment by Senators Jeff Merkley, Democrat of Oregon, and Carl Levin, Democrat of Michigan, that would impose tight restrictions on the ability of banks that hold clients’ deposits to trade stocks and make other risky investments for their own gain.

Democrats and their two independent allies control 58 Senate seats in the wake of Byrd's death, but Feingold opposes the bill, and Democratic Senator Maria Cantwell has yet to commit to voting for the reform package.

That leaves Democrats hunting for at least three Republicans to back the legislation, which needs 60 votes to pass in the 11-seat chamber.