A federal judge yesterday halted the scheduled firing, downgrading or reassignment of about 220 Washington-based employes of the Department of Housing and Urban Development, enjoining the agency from reduction-in-force (RIF) planning until next year.

U.S. District Court Judge June L. Green issued the permanent injunction against the RIFs after finding that HUD officials had failed to get congressional approval for the RIF, which HUD said it was conducting to correct "skills imbalances."

The American Federation of Government Employees (AFGE) and Rep. Martin O. Sabo (D-Minn.), who brought suit against the agency, contended that the RIFs would violate the HUD and Independent Agencies Appropriations Act for 1983. That act, according to AFGE, prohibits HUD from using fiscal 1983 funds "to plan, implement or administer any reorganization of the department without prior approval of the committees on appropriations."

HUD had no comment, pending a study of the judge's order. Green had issued a temporary restraining order earlier, blocking the RIFs that had been scheduled to take effect Oct. 31.

Union officials and HUD employes speculated that the agency might "reconsider" its plans when Green's injunction expires Jan. 1, 1983. But Patrick Korten, spokesman for the Office of Personnel Management, left the door open to a court appeal, saying the government's case "doesn't end here."

About 40 HUD employes gathered outside the HUD building yesterday afternoon for a news conference and informal celebration of the court order. They wore anti-RIF buttons and chanted union slogans critical of the agency and the president.

"This is not a victory for HUD employes," said Gregg Holman, a coplaintiff in the suit and a spokesman for AFGE Local 476. "This is a victory for every recipient of HUD services." Prior to Green's order, Holman was scheduled to be downgraded from a GS 11 civil rights investigator to a GS 5 clerk.

AFGE and HUD employes argued that the RIFs were not economy measures but an attempt to curtail fair housing, community development and housing assistance programs that AFGE says are unpopular with the Reagan administration.