The House ethics committee yesterday chastised the Democratic lawmaker who filed a complaint this year against Majority Leader Tom DeLay (R-Tex.) and warned all House members they might be sanctioned if they lodge complaints that contain innuendo, speculation or "conclusory statements."

Some Democrats and watchdog groups said the committee's four-page letter could have a chilling effect on the House's self-policing apparatus, even in cases where a lawmaker may have violated ethical standards.

The bipartisan committee's chairman and ranking Democrat acknowledged that some of the allegations made against DeLay in June by Rep. Chris Bell (D-Tex.) were valid. Bell's complaint prompted the ethics panel on Oct. 6 to admonish DeLay on two counts -- one involving the use of a federal agency in a Texas partisan squabble, the other for his conduct that suggested political donations might influence legislative action.

But the validity of the allegations, yesterday's letter to Bell said, "does not mitigate your violation" of a House rule that says complaints against fellow lawmakers "shall not contain innuendo, speculative assertions or conclusory statements."

"This is a serious matter," said the letter, signed by ethics committee Chairman Joel Hefley (R-Colo.) and top Democrat Alan B. Mollohan (W.Va.). "The committee is putting all members on notice of the need to comply" with the guidelines. "All members are also now on notice that violation of any of those rules is a basis for summarily rejecting a complaint . . . and depending on the circumstances, may also be the basis for initiating disciplinary action against the member who makes the filing."

The letter said the rule about innuendo and conclusory statements has been in effect for 10 years, but it never resulted in a complaint being dismissed nor prompted "any interpretations" by the ethics panel.

The letter said Bell's complaint contained several exaggerated charges against DeLay, including bribery. Upon investigation, it said, the facts "did not come even close to supporting this extremely serious claim."

Melanie Sloan, executive director of Citizens for Responsibility and Ethics in Washington -- which helped Bell draft his complaint against DeLay -- said last night the committee's letter places too great a burden on a lawmaker who files a complaint, suggesting that every allegation must be fully proved rather than leaving that task to the panel. House rules bar groups and people outside Congress from filing ethics complaints against lawmakers.

The letter took no official action against Bell, who lost his reelection bid this year and is retiring from Congress. Bell said in a statement: "We are pleased that the bi-partisan Ethics Committee acted to admonish Mr. DeLay for his unethical conduct in response to the complaint I filed in June. . . . I gladly accept the Chairman and Ranking Member's Letter of Clarification of the Committee's rules on the proper procedure for filing an ethics complaint."