The $7 million race for governor of Virginia is entering its final 10 days with a barrage of TV advertising, much of it negative and tailored to do in a few seconds what the two candidates have tried to accomplish in months of campaigning.

"I told my family it's going to get nasty," said Gerald L. Baliles, the Democratic candidate, this week as he discussed a race that, partially by design of his strategists, has been surprisingly low key.

For Republican Wyatt B. Durrette, hoping to ignite a spark in what many of his supporters say has been an effort hobbled by internal disputes, the final flurry of TV ads is crucial. His advisers say the commercials should build on momentum that they say Durrette finally has achieved and that they say will push him ahead of Baliles, who has a strong lead in most polls.

The Democrats, whose ticket for the first time includes a black and a woman, scoff at claims of GOP momentum, although Baliles has said that the Republicans should narrow the 19-percentage-point gap that a Washington Post poll gave him last month.

"Wyatt's going to have to do something pretty dramatic to turn it around," said David Doak of Washington, Baliles' media consultant.

Durrette's TV ads will attempt to do that with a blunt, negative message, charging that Baliles, the former state attorney general in the administration of Gov. Charles S. Robb, is a big-spending liberal, a national Democrat whose conservative rhetoric hides the specter of large tax increases. Durrette says Baliles has lied about his own and Durrette's legislative records.

Baliles is countering with his own negative ads, alleging that Durrette, who represented Fairfax County for six years in the 100-member House of Delegates, does not have the experience to be governor, has changed his position on major issues and has not won an election in a decade.

"Knowing Jerry, I expect the . . . last-minute attempt to smear our record," said Durrette adviser Edward S. DeBolt of Arlington. DeBolt said he was not surprised by negative Democratic ads. "The best thing in the world for Republicans is to see how mean and spiteful Jerry is," he said.

That negative theme is being echoed in the two other statewide races -- for lieutenant governor and state attorney general -- as the Democrats and Republicans trade charges over their broadcast ads.

"It's low sleaze," fumed consultant Robert Squier of Washington this week as he complained that his client, Mary Sue Terry, the Democratic nominee for state attorney general, was being unfairly attacked in radio ads by her Republican opponent, W.R. (Buster) O'Brien.

Squier said the GOP ads, which note that Terry does not belong to the Virginia Bar Association, may confuse voters into assuming Terry does not belong to the Virginia State Bar, which all lawyers practicing in the state -- including Terry and O'Brien -- must join. The O'Brien campaign said it stands by its ad.

There also have been sharp exchanges over the ads placed by state Sen. John H. Chichester of Stafford County, the GOP nominee for lieutenant governor. This week he launched a new attack on his Democratic opponent, state Sen. L. Douglas Wilder, reminding voters of Wilder's ownership of vacant properties in Richmond and of his 1978 reprimand by the Virginia Supreme Court for mishandling a lawsuit for an accident victim.

"It reminds me of that saying that people in glass houses should not throw stones," Wilder's campaign manager, Paul Goldman, fired back. "Mr. Chichester is the only statewide candidate to be fined for unlawful conduct. We have run a positive campaign and not brought this up," Goldman said.

Chichester's Fredericksburg insurance firm was fined $250 after an employe violated a state insurance law by writing a policy she was not licensed to sell. Chichester subsequently introduced legislation changing sections of that law.

"I don't look for any surprises," said University of Richmond political scientist Thomas R. Morris. He said Baliles and Durrette "already have developed all the themes, attacks and counterattacks during the course of what has been a long campaign."

Baliles, 45, has managed to tie himself closely to Democratic Gov. Charles S. Robb (who under state law cannot succeed himself) and is "virtually running as the incumbent," said Morris, noting that this casts Durrette, 47, in the role of challenger.

"Baliles is not upset when people say the race is boring," Morris said. That perception has hurt Durrette, according to Morris and Republican leaders such as former Republican governor John N. Dalton, because it means that Durrette has failed to distinguish himself from Baliles and give voters a reason to turn to the GOP.

"That's where the Democrats have been effective . . . fuzzing up the issues," Morris said. "Democrats hope this campaign doesn't even heat up at the end," while the Republicans need a strong finish. The race, Morris said, could be decided on whether it "ends with a bang or whimper."

Republicans and many Democrats initially assumed that Wilder, the first black to be nominated by a major party for statewide office in Virginia, could be defeated easily. Democrats and some Republicans have said Chichester's campaign style and the attacks on Wilder by prominent Republicans with segregationist backgrounds have been viewed as racially motivated and counterproductive.

Moreover, Wilder, who has virtually no campaign staff, has marshaled all his funds into a TV ad campaign that touts his 15 years in the legislature and shows him with several slow-talking deputy sheriffs who proclaim Wilder the choice of the state Fraternal Order of Police. The ad is widely seen as one of the most effective in the campaign.

More than $10 million, much of it spent producing ads and buying televisions spots, has been spent in the campaigns, about $3 million more than the 1981 races that broke 12 years of Republican control of the governor's house. Baliles, a former Richmond area legislator, upset Durrette for attorney general in that race by 26,000 votes.

The race for governor has drawn hundreds of thousands of dollars from the Republican and Democratic national parties that see the contest as a test of political realignment in the traditionally Democratic South toward the Republican Party.

"Republicans are still in the mind-set of the 1970s," when they won at the expense of liberal Democrats, said political scientist Morris. He said the GOP has been slow to adjust to Virginia Democrats who are projecting a more moderate image under Robb.

Morris said the Republican "big spending, high tax" litany is not taking hold in Virginia this year because Robb, who polls show is more popular in the state than President Reagan, has overseen a progressive administration stressing fiscal conservatism.

DeBolt disagreed and said the GOP ads will make clear that Baliles "is not Chuck Robb." The race, DeBolt said, remains competitive. "If you're close enough in the hunt in the final 10 days, and I believe we are, I think the momentum has changed toward us."