Taking off his jacket and putting on a T-shirt emblazoned with the slogan "Save Our Swarthmore," Mayor Walter E. Washington met with several dozen tenants outside the apartment house at 1010 25th St. NW one evening last week.

"We cannot afford to let these (condominium) conversions move our people out of the city," the mayor told the group, many of whom were also wearing Save Our Swarthmore T-shirts.

The Swarthmore Tenants Association, which arranged the meeting, is trying to buy the 40-year-old, 88-unit building and form a cooperative. Raymond Howar, whose mother owns the building, says the family wants to sell the apartment house because rent control, inflation and rising utility costs have made its operation unprofitable.

Looking up at the Art Deco style building, the mayor asked, "Why would you want to leave?"

"We don't!" shouted someone in the crowd, which began cheering.

"If we lose this building, there will be very few places to go," Ann Loikow, president of the tenants' association, told the mayor, citing many examples of conversions of apartment buildings to condominiums and hotels and demolitions of apartment units in the Foggy Bottom area.

Washington said his office would work with tennants facing evictions and would try to find ways apartment buildings could be retained as rental operations or purchased by tenants.

"We can't have a city where good tenants can't live," he said. Washington said he lamented the fact that certificates of eligibility for condominium conversion had been obtained for 5,200 units during the first six months of 1978, compared with 1,100 units in all of 1977.

The Swarthmore's owner has applied for a certificate of eligibility for condominium conversion but was turned down because the rent levels weren't high enough for the building to be considered a luxury building, which is a requirement for conversion. The owner's appeal of the denial is still pending.

"For years I thought that if I could pay the rent I could live here," Nettie Mansker, an elderly resident of the Swarthmore, told the mayor. "NowI find that's not true."

Loikow told the mayor that if the tenant's association bought the building, the group would work out a plan for lower-income residents to remain, even if they couldn't afford to buy a cooperative apartment.

Under D.C. law, tenants who have expressed interest in buying their apartment building must be given a 45-day option on the property. On March 28, the Howar firm offered to sell the building to the tenants for $1.8 million. Although the 45-day period has expired, the tenants' association is still negotiating with Howar's lawyer, David Sacks.

The association has also met with officials of U.S. Department of Housing and Urban Development to discuss possible HUD financing for the purchase of the building by the tenants. The association is also working to raise money from other sources. The sale of the T-shirts and a bazaar, to be held Aug. 19 at St. Stephen's Church at 25th Street and Pennsylvania Avenue, are two fundraising efforts.

Before departing, the mayor presented Loikow with a T-shirt emblazoned with his campaign slogan, "Keep A Good Thing Going."