City Council members held negotiations on more than 40 proposed amendments related to rent control yesterday as the council prepared to take its first vote on the issue at its session today.

Among the proposals discussed yesterday were measures to exempt all single-family homes and vacant units from rent controls and to lift controls on all vacant units in four years.

Tenant groups have lobbied against such proposals for weeks, saying that any attempt to lift controls would make rental housing unavailable and unaffordable for some tenants, especially the poor and elderly.

The current rent control law expires April 30, and a bill before the council would extend the provisions of the current bill. Council Chairman David A. Clarke, who introduced the bill, has acknowledged having only six of the seven votes he needs to get his bill adopted unchanged by the 13-member council.

Under the Clarke bill, landlords would be allowed to make annual increases equal to the change in the metropolitan consumer price index, provided that the increase does not exceed 10 percent. Landlords also would be authorized to obtain additional rent increases based on making improvements to buildings renting vacant apartments.

The methods by which landlords can obtain increases have been the focus of proposed changes in the pending bill. For weeks Clarke and his supporters worked on the basis that they merely needed to compromise on one or more methods to win approval for the bill. But yesterday, Clarke's forces faced a new problem.

The other seven council members formed their own alliance and began negotiating in closed-door meetings on changes to the Clarke bill. The negotiations were being coordinated by John Ray (D-At Large), who had tried unsuccessfuly to get a controversial bill that would eventually eliminate rent control before the full council.

Charlene Drew Jarvis (D-Ward 4), chairman of the council's housing committee and reportedly the member designated to move a package of amendments today, said that the main concern was how the city can produce more rental housing. She said "there is not enough stimulation for housing production" in the Clarke bill."

"Rent control is going to win tomorrow," said Jarvis. "Nobody is preparing to elminate rent control."

Others, however, disagreed. John Wilson (D-Ward 2), who supports the Clarke bill, said that it appears that his side had been defeated.

"There is nothing to compromise because they don't have to give up anything because they have seven votes," Wilson said of the Ray group. "I think we've lost because I don't think we have the votes -- we never did -- and it was too hard to adjust to what people are asking for."

Wilson said that the proposal to exempt single-family homes from rent control would have the effect of displacing large low-income families that depend heavily on such housing.

Meanwhile, tenant activists, during a press conference, promised that any council member who voted for amendments that would "weaken" rent control would later face political opposition from an organized tenant action committee.

Later in the day, about 20 supporters of the Clarke bill marched in front of the Washington Board of Realtors' headquarters, 777 14th St. NW, to protest a newspaper advertisement in which Realtors proclaimed that a "schizophrenic Robin Hood" had "made rent control a bonus for the well-to-do and a treadmill for the needy."

Throughout the rent control debate, landlords have argued that rent control has caused the city's housing stock to decline and deteriorate. They also argued that landlords have been unable to make sufficient profits to maintain buildings.

Council members have been lobbied heavily by landlords and tenants, but some members said the tenant lobbyists had outnumbered landlords by about five to one.

Carol Schwartz (R-At Large), who was viewed by tenants as a possible seventh vote for the Clarke bill, said she received more than 200 telephone calls on rent control and about 2,000 cards and letters.

"We want to stimulate new housing and continue protections for those who are renters," said Schwartz. "This whole issue has been emotional and sometimes cruel. People in their 80s and 90s have called up in tears, scared to death that we're going to do away with rent control."