Two key D.C. City Council members yesterday unveiled a compromise no-fault auto insurance plan that appeared to have enough support to win council passage today.

Council members Nadine P. Winter (D-Ward 6) and William R. Spaulding (D-Ward 5), who voted against no-fault when the council defeated it by one vote two weeks ago, said they will offer their own plan today. Their proposal would require motorists to purchase no-fault insurance that would pay up to $7,500 in personal injury claims before a victim could sue for additional damages or for compensation for "pain and suffering."

Their plan won quick support from Council Chairman Arrington Dixon, sponsor of the original no-fault bill. Under Dixon's measure, motorists could not sue for pain and suffering except in the case of death or disfigurement. His bill would have provided up to $100,000 to pay costs of medical treatment for an injured motorist.

The right to sue for compensation for pain and suffering -- which accounts for many large insurance awards -- is a major component of the compulsory liability insurance bill initially passed by the council May 11. Yesterday, in an attempt to hold support for that measure, Wilhelmina J. Rolark (D-Ward 8), sponsor of the bill, said she would offer amendments that would lower the cost of premiums under her bill.

The council members acted against a backdrop of intense pressure yesterday, as lobbyists for both bills stalked District Building hallways in search of wavering votes.

All 13 council members reported that hundreds of phone calls and letters were still flooding their offices in response to the Government Employees Insurance Company-sponsored citywide mailing last week of 213,610 letters supporting no-fault.

Backers of Rolark's bill, which has been strongly supported by the city's association of trial lawyers, were in evidence as well. Attorney Larry Williams, the trial lawyers' registered lobbyist, was huddled with Winter and Spaulding late yesterday in an effort to sway them back to support of the Rolark measure.

As things heated up, some council members said the issue may have become too hot and that proponents of Rolark's bill might move to table the discussion rather than risk defeat. A move to delay the vote could "take several members off the hook until after the elections," one lobbyist said.

However, both Winter and Spaulding said they did not plan to support any delaying tactics. "That would put us back to square one," Spaulding said.

Winter has been exploring the idea of a compromise since the vote two weeks ago, and Spaulding joined her over the weekend. Both said yesterday they were not satisfied with either bill pending before the council. Winter drafted the basic elements of the proposal offered yesterday.

The two said their compromise $7,500 "threshold" for suits would allow seriously injured persons to be fairly compensated. Insurance lobbyists yesterday indicated that they would reluctantly support that figure.

No-fault proponents previously have opposed low thresholds because they have said such provisions encourage inflation of medical bills to reach the threshold level.

The Winter-Spaulding compromise also increased the minimum benefits a person could receive for lost wages from $1,000 a month to $2,000 and made several other changes, none of which affect the cost of insurance rates, according to insurance officials.

The compromise also requires motorists to carry at least $5,000 of regular property liability insurance to cover the cost of damages, which would be determined by who is at fault in an accident. The Dixon bill would not have covered damage to property.

"People want their cars fixed when someone runs into them," said an aide to Winter.

Meanwhile, Rolark's major amendment would bar insurance companies from using sex or marital status to determine what rates they charge their customers.

In addition, insurors would be required to sell insurance to all drivers with good driving records, regardless of whether they have ever had auto insurance. It is estimated that 40 percent of the city's 250,000 registered vehicles are owned by uninsured motorists.

"Rates are going to be the key," said Rolark, who said her amendment would reduce the cost of liability insurance.

None of the council members who voted for no-fault two weeks ago appeared to be changing positions yesterday, according to a variety of sources at the District building. Those members included Dixon, Betty Ann Kane (D-At Large), David A. Clarke (D-Ward 1), Hilda Mason (Statehood-At Large), H. R. Crawford (D-Ward 7) and Polly Shackleton (D-Ward 3).

Members who support the compulsory liability system include Rolark, John A. Wilson (D-Ward 2), Charlene Drew Jarvis (D-Ward 4), John Ray (D-At Large) and Jerry A. Moore (R-At Large).

Nine council members must be present to take action on a bill. A majority is required to pass any legislation. Whichever bill is approved today will have to come up for a second and final vote in two weeks.