The once sedate race in Virginia for a U.S. Senate seat turned a notch nastier tonight as Democratic candidate Richard J. Davis accused his Republican opponent Paul S. Trible of waging a campaign of "lies" and "character assassination" unprecedented in the state's modern history.

Trible responded by criticizing Davis for "name-calling."

The spark for tonight's attack was a recent campaign fund-raising letter put out by Trible, which Davis said implies that Davis defends special privileges for union officials who "commit violence and extortion." In a speech before a group of real estate lawyers here, Davis called this a "blatant, malicious lie.

"I'm very angry," the 61-year-old lieutenant governor said in an informal news conference after his speech. "I've never known character assassination to be a generally accepted practice in Virginia politics. I think I'm the first one subject to that kind of assassination and I'm simply not going to have it."

In his statement responding to Davis' accusations, Trible declined comment about the fund-raising letter. Instead, he said, "Evidently, Dick Davis has nothing of substance to say to Virginia . . . Do we want Virginia's future to be in the hands of someone who has to resort to name-calling because he has no substance to back him up . . . someone who can't address the issues because he can't understand them?"

Tonight's verbal skirmish is only the latest in a series of clashes over personal integrity that have marked the Davis-Trible contest, a race most political analysts are calling a dead heat. Last month, Davis accused Trible of a "lack of integrity" over another campaign fund-raising memo that said Davis' campaign workers had improperly solicited labor-union contributions at a New York meeting.

Davis, who has contended the meeting never took place, said tonight he intends to demand that Trible "look me straight in the eye" and defend the memo when the two candidates square off in their first debate Saturday in Williamsburg.

Trible, meanwhile, has accused Davis of taking the low road by seeking to imply that he shirked military service during the Vietnam War. Trible was excused from military service because of a deformity in his arm. Davis has made a point throughout the campaign of rolling up his sleeves and showing off his own bent left arm, while asserting that the handicap did not keep him from serving in the Marines during World War II.

While Davis' charges have kept Trible on the defensive for most of the last month, the 35-year-old Newport News congressman has recently attempted to regain the initiative by criticizing Davis' past. Today, Trible went to a boarded-up pawnshop in Davis' hometown of Portsmouth to assert that the Tidewater city had lost 3,619 jobs during Davis' six-year tenure as mayor there. During his own six years in Congress, Trible said, the two largest cities in his district, Hampton and Newport News, gained 12,000 jobs.

Trible was unable to point to any of Davis' policies as mayor that contributed to the alleged job loss, but maintained that "the cold, hard facts show that on the issue of jobs, my opponent has simply not delivered."

A Davis spokesman said later that Trible was using faulty numbers. "It's another attempt to distort the job picture in Portsmouth to mislead the people of Virginia," said Davis' press secretary, Will Marshall.