Several of Virginia's more prominent historians are rallying to protect the good name of Thomas Jefferson from a 177-year-old "rumor" that refuses to die.

In its latest form, the threat is contained in a forthcoming novel entitled "Sally Hemings" and a projected Warner Bros. television mini-series on the subject. The historians claim both will show -- inaccurately and scandalously -- that the Old Dominion's beloved son had a 38-year affair with Hemings, his black slave and alleged mistress.

"It will be a mockery of history," said Dumas Malone, a Pulitzer Prizewinning biographer of Jefferson.

"I am very upset," said historian and former Richmond Times-Dispatch editor Virginius Dabney. Robert Rutland, editor of James Madison's papers, said, "Those television people don't give a damn what they do to the national character."

The historians have written to CBS, which has purchased an option to buy the story of Jefferson and Hemings, and to Viking Press, which will publish "Sally Hemings" on June 21. They asked that the projects be cancelled.

Whether Jefferson did, in fact, father seven children by a beautiful, long-haired slave named Sally Hemings is still hotly disputed. In her 1974 best-seller "Jefferson: An Intimate History," historian Fawn M. Brodie wrote that the evidence for such a liaison is strong. In his five volumes on Jefferson's life, Malone concludes that the relationship was "utterly impossible."

In the shadowy space between fact and fiction, Viking Press claims "Sally Hemings," the first novel of poet and sculptress Barbara Chase-Riboud, is a "drama created by an American black woman. It is not an historical treatise."

What Chase-Riboud tries to do in her $10.95 novel, according to Viking publicity agent Victoria Meyer, "is convey sonething symbolic about the relationship between the races in America." The author is now in Paris and could not be reached yesterday for comment.

What bothers the Virginia historians is their fear that one woman's symbolism, as transmogrified by Hollywood writers, will become the definitive biography of Jefferson for the millions of Americans who learn their history from television.

"Scandal and sex can be exploited to great financial advantage. The public will always believe the story," said Malone. "You can never get it back. You can never stop it."

Warner Bros., which is now writing a teleplay for a possible two-part series on CBS, does not see how Jefferson's memory will suffer irreparable damage, according to legal affairs director Ed Hoffman.

"I would basically disagree with what the Virginia historians are saying," said Hoffman, in a telephone interview "All we are doing is developing a book into which a great deal of research went by the authorities."

The stories about Jefferson and his Monticello slave, which have survived since 1802 without the help of television were spread by President Jefferson's political enemies, according to Malone and other Virginia historians.

Malone has written that an Irishborn newspaperman in Richmond by the name of James Thomas Callender started "the slander" when he did not get an expected appointment.

"It is utterly impossible that Jefferson could have carried on in the presence of his own family in Monticello, being the kind of very moral and extraordinarily devoted family man he was," said Malone.

Historian Dabney, who has made speeches denouncing the Heming rumor, said that Jefferson's nephews admitted fathering Heming's children.

There is, however, a great deal of psychological evidence from Jefferson's letters that indicates the affair took place, Brodie contended yesterday in a telephone interview from Los Angeles.

Brodie, who sees no harm in a miniseries on the affair if it is faithful to Jefferson's genius, said that Jefferson's relationship with Heming "was a very longstanding, affectionate one which gave Jefferson much happiness."

Brodie and Malone yesterday gave opposite interpretations of a letter written by Jefferson in 1805 to his secretary of the Navy.

"You will perceive," Jefferson wrote, "that I plead guilty to one of their charges, that when young and single, I offered love to a handsome lady. I acknowledge its incorrectness."

Malone said Jefferson, who thus admitted the impropriety of a pass he once made at the wife of a friend, denied in the letter all other rumors about his sexual life, including the one about his liaison with Heming.

Brodie said Jefferson referred in the letter only to the pass he made at his friend's wife, and that he did not mean to deny that Heming was his lover.

"Sally Heming," according to Viking's spring book catalogue, is an "unashamedly romantic novel."

Malone said yesterday he thinks the televised version of the novel will be taken as historical fact by a "gullible public," no matter how romantic it is.

"What's the use of us (historians) trying to get history straight?" Malone asked.