When it became known last month that the city's three major real estate groups had begun a campaign to oust three City Council members no one had to ask why.

One answer is rent control.

Developers and real estate agents have pointed consistently to the District's 11-year-old rent control law as a damaging influence on the city's rental housing market. Along with the high rate of workers' compensation, rent control is at the heart of all pleadings that the District government -- particularly the City Council -- is anti-big business and discouraging economic development.

For years, they have complained that rent control takes the profit out of operating apartment buildings here -- only to hear politicians and tenants counter that "rich" landlords can better endure the financial pain than "poor" tenants.

Now the real estate brokers have another argument: rent control, says John T. O'Neill, executive vice president of the Apartment and Office Building Association, is hurting poor people. It is closing down the few remaining buildings where poor folks can afford to live. Those landlords who keep their buildings open, the argument goes, are cutting short repairs in order to maintain some profit.

The vacant shells once common only in poorer areas of Southeast can now be seen in ever larger numbers in the middle of the city -- above Columbia Road between 14th and 16th streets NW.

Here is landlord Emanuel Dickey, who has been convicted of housing code violations, talking about why his 56-unit building at 2523 14th St. NW is kept half-empty:

"Rent control is basically running poor people out of the city. What do you think the City Council is up to when they [legislate] rent control while there is no control on the price of oil, no control on the price I'm paying the plumber."

Tenants have another view. The problem is not rent control, they say, but landlord greed. "Landlords can make a 10 percent profit with rent control," said Roger Turpin of Washington Inner-City Self Help, which organizes tenants in 100 apartment buildings in the Columbia Heights area.

"Ten percent is a good profit, but it is not as much profit as landlords want and some of them get frustrated because they can't get more," Turpin said. "That's why they're closing up the bhildings. I'm working with people in one building where the landlord has 50 of the 77 units vacant. He wants them all to get out so he can convert it to a condominum. If they stay, he can't do that."

City officials walk a thin line on the issue. Housing director Robert L. Moore predicts that rent control will cause another wave of landlords to abandon buildings here this spring as high heating bills from a freezing winter leave them overburdened with debt.

He cited a $6 million jump, from $11 million to $17 million, in heating and electricity costs for public housing over the past two years as evidence of the kind of cash drain landlords faced even before the cold wave.

"Rent control," says Moore, "is a contributing factor to all these buildings being abandoned."

While it may even be the primary factor, he added, it is not the only one. Interest rates are high; it is difficult or impossible to borrow money for building improvements. Many tenants' earnings simply have not kept pace with inflation. In the first quarter of this year, Moore said, the rate of requests for public housing rose 147 percent, while the waiting list grew from 7,000 to 8,200 people.

Charlene Drew Jarvis (D-Ward 4), head of the City Council's housing committee, said the council is aware of the growing need for more housing and of the charge that rent control is to blame. She said she did not believe that rent control would be abolished, however, or replaced by rent ceilings.

Council reluctance to do away with rent control has led three major real estate organizations here to target three council members for defeat: David A. Clarke (D-Ward 1), Polly Shackleton (D-Ward 3) and William R. Spaulding (D-Ward 5). Even if the move is successful, some say, it won't assure the end of rent control.

The poor, most of them black, are leaving Washington, and being replaced in many renovated neighborhoods by young professionals, many of whom are white. Rent control has become a last-stand issue for politicians to whom it is a symbol that many poor Washingtonians are being eased out of an increasingly popular and attractive city that has been their home for years.

Mayor Barry says that on the one hand he can't blame property owners in a free enterprise system for wanting to sell or lease their property to someone who may be able to pay more than poorer, longtime tenants.

"If we had a way to take care of the displaced people, the benefits would equal the losses. But in most instances," Barry says, "you don't have any place to put them. People just wander around the city. They double up with relatives and friends. That's no way for people to be living."