Virginia's two senatorial opponents circled through the mountains and flatlands of the state's rural countryside yesterday, leaving it to political seconds to assail the enemy and each other.

Former Gov. Mills E. Godwin lashed out at Democrat Andrew P. Miller during a day-long swing by Republican John W. Warner through conservative, agricultural Southside. The speech coincided with an attack, delivered on Miller's behalf, by state Sen. J. Dudley Emick in Fincastle as Miller toured the Shenandoah Valley.

Speaking in South Boston, an area where Miller has strong conservative support, Godwin lambasted the former state attorney general, tying him to Sen. George McGovern, former Lt. Gov. Henry Howell and President Jimmy Carter, and painting Miller as an opponent of Sen. Harry F. Byrd jr.

Godwin called Miller a man who "puts party over principle" and praised Warner as a conservative in the Virginia tradition typified by himself and Byrd.

Godwin argued that Miller's support of previous Democratic candidates such as Howell, who ran last year for governor, and Carter in 1976, were reasons why Miller would be a poor representative of Virginia's conservatives in Washington. He also pointed to Miller's support of Byrd's Democratic opponents in 1972 and 1976.

Godwin failed to mention that Miller's support for Howell last year was lukewarm and that Miller is on poor terms with Carter. The tie to McGovern was more curious. When McGovern was the Democratic presidential nominee in 1972 Miller announced he would cast a write-vote for John Warren Cooke, speaker of the Virginia House.

In Fincastle, Enick, addressing a luncheon meeting of Democrats, said, "In my own mind I am unsure whether he (Warner) is dumb or deceitful. I cannot categorically say he's totally dumb because in the television commercials I see (Sen.) Bill Scott does not appear one time . . ."

Enick, who as Miller later said is "noted for his color"ful language," followed several other state Democratic leaders hosting Miller visits along the campaign trail in doing what Miller is not doing himself - attacking Warner and the Republicans in increasingly blunt language.

Referring to Godwin, Emick said "If you're looking for consistency in his career, then you better take another look. He is now condemning Andrew but in my presence he said Andrew was one of the best attorneys general we ever had." "In my last year of law school, I campaigned diligently for (Godwin)," Emick also said. "But in 1975 when I was running for the state Senate - he flat out slipped a knife in my back. He is capable of doing it . . . he is doing it to Andrew."

Godwin, a Democrat until 1972, also took time yesterday to criticize Senate Majority Leader Robert Byrd (D-W.Va.), who appeared several days ago for Miller in the Tidewater area.

"He's the gentleman, if my memory doesn't fail me, who articulated the virtues of the Labor Reform Act," Godwin said. "He's also one who spoke for the Panama Canal Treaty. It's this type of leadership, tied to the national administration, that they want John Warner's opponent elected to come to Washington (to) help support."

Warner's Southside swing, part of an intensive statewide campaign in the final week of the race, has left the Republican perceptably tired. By Sunday he will have covered every region except Northern Virginia and Tidewater, where he will travel the final two days of the race.

Miller, too, is scheduled to visit all 10 congressional districts at least once, with more time allocated to rural areas and the populous Tidewater region than to vote-rich Northern Virginia.