The House yesterday voted 407 to 1 yesterday to authorize its ethics committee to conduct a broad investigation into allegations of improper sexual conduct and use or distribution of illegal drugs by congressmen or House employes.

Reacting speedily to allegations made over the past two weeks by former congressional pages and to an investigation of an alleged cocaine ring on Capitol Hill, leaders of both parties ordered the resolution brought to the floor yesterday without the usual preliminary action by the ethics and Rules committees.

House Majority Leader Jim Wright (D-Texas) called on the ethics committee to "move as expeditiously as possible . . . to establish the truth and make official recommendations concerning allegations made against . . . members and employes of the House of Representatives."

The resolution gives the committee sweeping subpoena powers, similar to those used during the panel's previous, sensitive inquiries into members' alleged activities in the Abscam and Koreagate scandals.

In addition, the resolution authorized the committee to coordinate its inquiry with the Justice Department and enter into agreements with Justice or other investigative agencies that would permit prompt delivery of necessary information.

Committee Chairman Louis Stokes (D-Ohio) told the members that such agreements would be necessary for the committee "to negotiate to get information from Justice while the latter is proceeding with prosecutorial" activities.

In return, the committee agreed to limit access to that information "to such members of the committee or other persons as the committee may designate."

That provision, a congressional source said yesterday, could come into play if a member of the ethics panel, formally called the Committee on Standards of Official Conduct, also were involved in an allegation under Justice Department investigation.

Because that provision gave Justice the right to determine who in Congress had access to FBI investigative material, Rep. Henry B. Gonzalez (D-Tex.), cast the only vote against the resolution.

Justice has been looking into allegations presented to it by at least three former pages. One of them, Leroy Williams Jr. of Little Rock, has told ethics committee investigators and the FBI that he had sexual relations with three members of Congress and arranged two liaisons with prostitutes--one for a senator and another for a congressional aide.

Last week, Williams acknowledged that he failed parts of an FBI lie detector test on these allegations and said in earlier interviews with The Washington Post that he had exaggerated portions of his story.

The Drug Enforcement Agency and the D.C. police have been conducting a separate investigation into an alleged cocaine distribution ring operating on Capitol Hill. Yesterday's resolution authorizes the ethics committee to look into those allegations, too.

Rep. Robert K. Dornan (R-Calif.), who last year permitted a D.C. policeman to claim he was a Dornan aide while conducting an undercover investigation of cocaine distribution, said yesterday that he would present to the ethics committee tomorrow information he had obtained from investigators on congressmen alleged to be cocaine users.

Last week Dornan sent a confidential letter to the House Select Committee on Narcotics Abuse and Control, of which he is a member, informing the panel that investigators had identified seven members of Congress and two former members as cocaine users. Dornan did not give their names, just the states from which they came.

He had said he would present the names to the committee yesterday, but in a closed session, he failed to do so, and no member asked him, according to Committee Chairman Leo C. Zeferetti (D-N.Y.). "If he wanted to give them," Zeferetti said, "we thought he would."

There were new allegations over the weekend, this time coming from a former page who told investigators of a sexual proposition made to him by an individual who at the time worked for a House committee.

The former staff member said yesterday that his relationship with the page was a "friendship that just kind of developed." Asked if he propositioned the page, as alleged, he said , "I can't go into that at this time."