Civil rights attorney Joseph L. Rauh yesterday accused Congress of unconstitutionally trying to circumvent Supreme Court decisions on school busing plans by blocking the Department of Health, Education and Welfare from terminating federal funds to segregated school districts.

He said an amendment to the labor - HEW appropriations bill passed late last year would halt HEW's administrative power to cut off funds and "would turn back the clock" on Supreme Court decisions involving school busing for desegregation purposes.

Justice Department attorney Robert Franziger said, however, that the amendment merely transfers the authority for enforcement from HEW to the Justice Department, which could instead file suits enforcing desegregation plans.

Rauh is asking U.S. District Senior Judge John J. Sirica to rule the amendment unconstitutional and block its enforcement. Sirica said he would rule later.

Rauh said HEW officials involved in civil rights policy agreed with him that it would soften the enforcement of civil rights laws, although Franziger later disputed that characterization of HEW testimony.

"There's really a constitutional crisis on this subject," Rauh said. "I cannot think of a more clear legislative intrusion into the judicial arena."

Franziger said there is no evidence that the new amendment has brought school desegregation to a standstill, and said it actually affects only a small number of cases.

The purpose of the amendment, he said, is not to avoid school busing but to put the enforcement of school desegregation into the judicial process.

Such cases involve "a complex and factual history that should be adjudicated in federal court," Franziger told the judge. He said Congress made a "policy choice" that HEW should not be terminating funds to segregated school districts.