Four years ago, when the D.C. City Council adopted a rent control law, tenant groups accused council member John Ray (D-At Large) of "pulling a fast one" with the successful last-minute introduction of an amendment that increased the amount of rent that landlords can charge for a vacant apartment.

Determined to avoid surprises this time around, tenant groups have compiled a list of "killer amendments" that they want council members to reject if the proposals are raised during the floor debate next month. Attached to the list is a scorecard for recording council members' positions on each amendment prior to the formal rent control vote.

Tenants, fearing that higher rents would displace some residents, oppose amendments that would lead to increases.

Their list of "killer amendments" includes changes that would lift controls on rental units as they become vacant, would exempt single-family houses from controls, would raise the increases allowed for landlords who file hardship petitions and would allow tenants to be evicted without cause.

The city's rent control law, which affects 120,000 units, expires on April 30, and tenants are getting anxious about the big vote that will determine whether the protections offered by the current law will continue.

The council's Committee on Consumer and Regulatory Affairs voted last week to send Chairman David A. Clarke's bill to the full City Council.

His bill would extend the provisions of the current law for four years. But Clarke acknowledges that he has only six of the seven votes he needs to get the bill adopted and that a compromise, in the form of amendments, may be needed to attract the seventh vote.

Some tenants are convinced that the council's procedural handling of the vote may have a major impact on what happens to the Clarke bill.

The current law was adopted five months before the previous rent control law expired. But this time, the council is pressured for time.

The council knows it must adopt emergency legislation to make certain that something is in place when the current law expires. Meanwhile, if the council makes no move to waive its rules, the first of two readings on permanent legislation will take place the day the law expires and during a night council meeting.

"That's the best bargaining position in the world for those who want to change rent control," said Mark L. Plotkin, a Ward 3 resident and strong rent control advocate. "Everbody wants rent control to continue after April 30, so they those who seek to change the law can get compromises and concessions where they never would have attempted them under the normal course of business."

The Emergency Committee to Save Rental Housing has asked that the council complete final action on a rent control law by April 16. Clarke has asked Ray, the leading proponent of changing the law, to agree to begin action on a rent control bill at a special meeting next Tuesday. Ray had not responded to that request by late Tuesday of this week.

Perhaps the key to predicting when the council will act rests with the answer to one question: Why has Clarke been unable to get seven votes for his bill?

City Council member Charlene Drew Jarvis (D-Ward 4), chairman of the council's housing committee and one of several members who has not publicly taken a position, said most council members believe that rent control has protected tenants but have the "feeling that housing stock has deteriorated under rent control and that that issue must be addressed."

Landlords, who argue that they have been unable to obtain sufficient income to properly maintain properties, have urged the council to add provisions that authorize greater increases above base rents.

Last week, in an attempt to get a seventh vote, Clarke and his supporters offered to compromise by allowing the minimum rate of return allowed for landlords who file hardship petitions to increase from 10 percent to 12. The Clarke group was willing to allow the base rent date to be changed from 1973 to 1980.

But because all attempts at a compromise failed, council members say that only one thing is certain -- the council plans to adopt some type of rent control law.