Citizens for Responsibility and Ethics in Washington says in its report that the 13 members, among them Senate Majority Leader Bill Frist (R-Tenn.) and House Majority Whip Roy Blunt (R-Mo.), might have violated a variety of congressional ethics rules.

The bipartisan list includes three Californians: Reps. Richard W. Pombo (R-Tracy), Maxine Waters (D-Los Angeles) and Randy "Duke" Cunningham (R-Rancho Santa Fe).

Cunningham is one of two House members whose residences have been searched as part of separate federal criminal investigations. The other, Rep. William J. Jefferson (D-La.), also is named on the watchdog group's list.

Three of those named on the list — Sen. Conrad Burns (R-Mont.) and Reps. Bob Ney (R-Ohio) and Tom Feeney (R-Fla.) — were cited for their dealings with onetime super-lobbyist Jack Abramoff, who is the subject of congressional and federal grand jury investigations. Abramoff was indicted last month on fraud charges relating to a Florida business deal. He has pleaded not guilty.

"They all violated ethics rules," Melanie Sloan, the watchdog group's executive director, said of the 13 members of Congress on its list. She criticized both political parties for what she said was a failure to police ethics.

James Pendleton, a spokesman for Burns, dismissed the group's report as "pure politics." Ney's press secretary, Brian Walsh, said: "We don't give Melanie Sloan and her liberal organization an ounce of credibility."

Its report, titled "Beyond DeLay: The 13 Most Corrupt Members of Congress," is based on news articles and other documents, the watchdog group said. It made the report available to the Los Angeles Times.

Citizens for Responsibility and Ethics in Washington "was compelled to research and release a report on these corrupt members because the ethics committees in both the House and Senate are completely inert," Sloan said. "The report calls for the House and Senate to act to investigate and take appropriate action against them for these violations of the rules."

The watchdog group has been outspoken in criticizing House Majority Leader Tom DeLay (R-Texas) for what Sloan calls his ethical lapses.

"Nonetheless, we recognize that Rep. DeLay is not the only member of Congress whose behavior merits scrutiny," the report says. "There are a significant number of other members who have engaged in similarly egregious conduct, thus the name of the report: 'Beyond DeLay.' "

It says the group's goal is "to galvanize both the House Committee on Standards of Official Conduct and the Senate Select Committee on Ethics into action. The ethics committees have lain largely dormant over the past years despite the often appalling conduct of their members."

Sloan expressed impatience with both parties. "Democrats are just as much to blame as Republicans for the current ethics deadlock. The Democrats won't file ethics complaints against even the most egregious violators like DeLay and Ney…. The Democrats are spineless," she said.

Sloan said she had been unable to persuade any member of the House to file ethics complaints that the watchdog group has drawn up against Ney and Cunningham. House rules do not permit outside groups to file complaints.

"It is outrageous that outsiders can't file complaints, since Congress has demonstrated its unwillingness to police its own conduct," Sloan said.

In 2004, Sloan helped then-Rep. Chris Bell (D-Texas), a lame duck, file a complaint against fellow-Texan DeLay. The House ethics committee admonished DeLay, but also said Bell had violated a House rule by filing a complaint containing "innuendo, speculative assertions or conclusory statements."

The Senate does permit outside complaints, but Sloan said they were routinely dismissed as "speculative."

Both ethics committees can initiate investigations on their own without a complaint. Such investigations tend to be confidential in the early stages.

A spokesman for the House ethics committee said he could not speak on any matter that may be pending before the committee. Rob Walker, chief counsel for the Senate Select Committee on Ethics, declined to comment.

The 13 members of Congress recommended for investigation by the watchdog group are:

• Sen. Bill Frist: The report accuses him of violating federal campaign finance laws in how he disclosed a campaign loan. It also calls for an inquiry over his recent sale of stock in HCA Inc., his family's hospital corporation. The sale has raised questions about possible insider dealing. Frist aides confirmed Friday that the SEC was investigating. They have denied claims of campaign finance violations.

• Rep. Roy Blunt: The report criticizes him for trying to insert provisions into bills that would have benefited, in one case, a client of his lobbyist son and in another case, the employer of his lobbyist girlfriend, now his wife.

• Sen. Conrad Burns: The report says that questions arose over $3 million in appropriations he earmarked for an Indian tribe in Michigan that was a client of lobbyist Abramoff. The senator received substantial campaign contributions from Abramoff and various clients.

"Sen. Burns did nothing wrong, and any accusation to the contrary is pure politics," said James Pendleton, his director of communications. He said Burns had earmarked the appropriation at the request of the Michigan congressional delegation.

• Rep. Bob Ney: The report says the chairman of the House Administration Committee went on a golf outing to Scotland in 2002, arranged by Abramoff, at a time when the congressman was trying to insert a provision into legislation to benefit one of Abramoff's tribal clients.

Ney reported to the House that the trip was paid for entirely by the National Center for Public Policy Research, a conservative think tank, which denied paying any of the costs. Ney has said he had been duped by Abramoff.

• Rep. Tom Feeney: The report says he incorrectly reported that a golf trip to Scotland with Abramoff in 2003 was paid for by the National Center for Public Policy Research, which denied it. A Feeney aide said the congressman had been misled. Questions also have arisen about two other privately funded trips.

• Rep. Richard W. Pombo: He paid his wife and brother $357,325 in campaign funds in the last four years, the report says. He also supported the wind-power industry before the Department of Interior without disclosing that his parents received hundreds of thousands of dollars in royalties from wind-power turbines on their ranch.

Brian Kennedy, a spokesman for Pombo, said that "each of the charges is baseless." He called the watchdog group "a Democratic attack group, and all of their charges should be taken with a grain of salt."

• Rep. Maxine Waters: The report cites a December 2004 Los Angeles Times investigation disclosing how members of the congresswoman's family have made more than $1 million in the last eight years by doing business with companies, candidates and causes that Waters has helped. Before publication of the Times investigation last year, Waters declined to be interviewed, but said of her family members: "They do their business, and I do mine."

• Sen. Rick Santorum (R-Pa.): The report says he encountered controversy over disclosures that Pennsylvania taxpayers paid for his children's schooling while they lived in Virginia. Santorum maintained he did nothing wrong, and has pulled his children out of the school, according to reports.

• Reps. Randy "Duke" Cunningham and William J. Jefferson: Both congressional veterans are under federal investigation.

Cunningham, who has announced that he will not run for reelection, faces questions over his dealings with a defense contractor who allegedly overpaid him when he purchased Cunningham's house. Jefferson is under scrutiny for his role in an overseas business deal. Normally the House ethics committee does not hold inquiries while criminal investigations are underway.

• Rep. Charles H. Taylor (R-N.C.): The report says that questions have been raised about his private business interests, including a savings and loan in Asheville, N.C., and personal business interests in Russia.

• Rep. Marilyn N. Musgrave (R-Colo.) and Rep. Rick Renzi (R-Ariz.): Both second-term House members encountered criticisms tied to campaign activities, the report says.

Musgrave was accused of misusing her congressional office for campaign purposes. Renzi was accused of financing portions of his 2002 campaign with improper loans.