After three months of mostly mild campaigning, Republican primary candidates for Northern Virginia's two congressional seats last week began stiring up considerable political froth.

With the Tuesday primaries less than a week away, Republican candidates in the 8th and 10th District races have splashed one another with accusations of malice and misrepresentation.

"They've gotten down to mudslinging," Del. Martin H. Perper said of the campaign waged in the 10th District by supporters of Arlington attorney Frank Wolf.

In the primary, Wolf is challenging Perper and Falls Church Mayor Harold Miller for the right to run against incumbent Democratic Rep. Joseph Fisher this fall.

"He (Wolf) doesn't want to throw the spitballs, he just makes them and gives them to somebody else to throw," claimed Perper, who says Wolf's supporters have raised "nasty, picayune" questions about his (Perper's) educational background and his divorce eight years ago. "It is hypocrisy of the greatest kind."

Wolfe denies that he or any of his staff have taken cheap shots at Perper. Just the opposite is true, says Wolf, who adds that he was "hurt personally" by a letter of endorsement that Perper's people mailed recently that contained "false accusations" about Wolf.

Signed by the chairwomen of two Virginia women's groups, the letter called Wolf one of womanhood's "worst enemies" and further stated that Wolf "advocates the abolition of the Social Security system despite the hundreds of thousands of widows and retired women who are financially dependent on it."

"I am a strong supporter of the Social Security system," said Wolf. "My father, who is a retired policeman in Philadelphia, is on Social Security. My mother-in-law who is 82 years old has been on Social Security for four years."

Miller, who has conducted a less energetic campaign than either of his two opponents, has stayed out of the fray. "I don't run that kind of campaign, he said.

In the 8th District, the two candidates fighting for the Republican nomination to challenge Democratic incumbent Rep. Herbert E. Harris -- who along with Fisher nominated at Democratic conventions recently -- also have traded political punches.

Robert Thoburn, who runs a conservative Christian school in Fairfax County, last week attacked the voting record of Stanford E. Parris, who served in Congress for two years before losing to Harris in 1974.

Thoburn claims that although Parris says he opposes federal funding of abortion, Parris voted in 1974 against a bill that would have prohibited the use of federal funds for that purpose.

"I'm not about to defend my voting record to Bob Thoburn, I don't care what he says," said Parris last week. "That vote is not the issue . . . the issue is electability against Herb Harris in November."

Parris, a Fairfax County lawyer, was a member of the county Board of Supervisors from 1964 to 1967 and served in the Virginia House of Delegates from 1969 until 1972. Parris credits that past experience as well as his moderate-conservative image with the endorsements he has received from 12 of the 15 elected Republican officeholders in the 8th District.

"One of the biggest problems I have is that everybody tells me I don't have a problem. They say there is no possible way you could lose this primary," said Parris. "But you know what happens when you start looking ahead to the superbowl. You get knocked off in the preseason game."

Thoburn, who was defeated last fall when he ran for reelection to the House of Delegates, does not consider himself an underdog in this contest, although he has unsuccessfully sought the 8th District congressional seat twice before. Two years ago he placed third in the Republican primary behind Fairfax County Board Chairman John F. Herrity, who went on to lose in a bitter campaign against Harris. Thoburn says his lack of endorsements does not bother him.

"Parris has got the officials, I've got the voters," said Thoburn, whose rock-ribbed conservatism has earned him a loyal following and some political critics.

"I think Bob's perception of solutions to some public problems is a little inflexible and unworkable," says Parris. Ralph Griffith, Parris' campaign manager, is more blunt in describing Thoburn.

"He's a doomsayer and a shouter," said Griffith. "My man is clam."

In the 10th District, Frank Wolf has gotten the lion's share of endorsements from party officials, even though he has never held elective office.

"Frank has worked like a dog for the party and most people think it is his turn," said Judy Shreve, the 10th District Republican chairman at the start of the campaign.

Both Perper, who is serving his second term in the Virginia House of Delegates, and Miller, who has been mayor of Falls Church since 1974, are betting that their incumbency will carry more weight with voters than officials blessings.

But in primary races where less than 10 percent of eligible voters generally go to the polls, party support is sometimes all the support a candidate can depend on.

"The primary is an orgy of organization," says Parris. "While the people of authority (in the 8th District) are almost without exception on my side, the question is will the Republican Party deliver on my behalf on June 10?"