A federal judge yesterday blocked Prince George's County from demolishing the blighted and abandoned Baber Village low income apartment project that has become a symbol of county opposition to concentrated housing for the poor.

County officials immediately vowed they will continue the fight to rid the Seat Pleasant community of the dilapidated four-building project.

The U.S. Department of Housing and Urban Development, which sought yesterday's federal court order in Baltimore, has been attempting to save the project, claiming demolition would be a "a total waste."

U.S. District Court Judge James R. Miller Jr., who issued the preliminary injunction, also set down several conditions that HUD must meet. HUD must see that there is security for the structures, correct health and safety hazards and proceed expeditiously with rehabilitation plans, the judge ruled. He ordered both sides to meet with him in about two weeks to discuss the status of the controversy.

The county has been fighting since last fall to demolish the project which county officials term "a health hazard and an ill-conceived idea."

The Prince George's County Housing Authority had proposed to HUD that the project be razed and replaced with new, smaller dwellings. But a HUD inspection team concluded it would be "far less costly" to rehabilitate the complex.

Last week HUD Secretary Patricia Roberts Harris moved personally onto the battleground with an announcement that HUD would renovate and restore Baber Village. HUD attorneys immediately moved into federal court to block demolition.

Those actions collided head-on with the wishes of County Executive Winfield M. Kelly Jr. He prefers expansion of the program in which low-income families are scattered throughout the county in apartments and given vouchers for rent payments, according to aide John Lally.

Lally said rehabilitation of Baber Village would mean "throwing good money after bad." Another Kelly aide has said that such projects "ghetto-ize the needy."

Baber Village, built in 1969 at Central Avenue and Cindy Lane in Seat Pleasant, is a complex of three-story garden apartments designed to avoid the barrenness of massive high-rise housing projects.

But within two years, some of the apartments had been condemned and the project, according to the County Council, was in a "serious state of physical and sociological deterioration." Two and three families were living in units designed for one and the county was forced to send seven special buses each day to transport children to school.

Meanwhile, Prince George's County was drawing people seeking low-priced housing and apartments that were becoming almost impossible to find in the more affluent counties surrounding the District.

Kelly was trying to fight that trend with an appeal to middle-class home-owners to his community, "junior executive" types, as he calls them.

Two years ago, the buildings were empty, and one was demolished. But Harris has made rehabilitation a hall-mark of her administration and says she considers "demolition a failure of policy."

HUD already has met some of the conditions set down in the judge's order, according to HUD's acting area director Thomas R. Hobbs. A 24-hour security patrol has been posted at the project and "much" of the complex has been boarded up, Hobbs said.

Hobbs said a special HUD team is prepared to begin discussions next week with the county housing authority on rehabilitation plans and could begin rehabilitation in 12 to 14 weeks.

Hobbs said HUD "is prepared to discuss options . . . such as reducing the density of the project," but he emphasized that demolition is out of the question.

Told of that, Kelly aide Lally said, "Then, we'll see them in court."