Rep. Charles C. Diggs Jr. (D.Mich.) yesterday asked the House ethics committee to dismiss charges against him because the panel is "without jurisdiction" to punish him for offenses committed prior to his election to the current Congress.

Diggs and his lawyers, in filing motions before the Committee on Standards of Official Conduct, said constitutional principles, precedents of the House and views of the Supreme Court support their contention the House cannot punish Diggs for what occurred prior to his reelection.

Diggs was convicted last October, and sentenced to three years in prison for taking salary kickbacks from his staff, but he was reelected in November after his conviction.

The House earlier this year voted to turn over the question of whether Diggs should be disciplined or expelled to the House committee. The panel brought 18 charges of misconduct against Diggs on April 4 and gave Diggs 21 days to respond.

In addition to responding that the committee is without jurisdiction, Diggs asked the committee for a bill of particulars on the 18 charges, questioned whether some information came from a grand jury investigation and moved that the committee defer action until the appeal of his conviction is final.

The committee is meeting next Wednesday and may act on the motions then. However, in late March, the committee turned downby a 9-to-3 vote a move to delay action until Digg's appeals are exhausted. In their brief, Diggs' lawyers said the House precedents show reluctance to punish offenses committed prior to an election.

They cited, for instance, the 1925-1926 case of John W. Langley of Kentucky, who was convicted for conspiracy and then reelected to the house. A select committee formed at that time wrote, "It must be said that with practical uniformity the precedents in such cases are to the effect that the House will not expel a member for reprehensible action prior to his election as a member, not even for conviction for an offense." Langley later resigned.

"We would submit that the peoples' choice may not be dictated by others, may not be unconstitutionally restricted by others and may not be overruled by others," Diggs' lawyers argued in their brief. CAPTION: Picture, REP. CHARLES C. DIGGS JR. . . . argues panel lacks jurisdiction