The high cost of campaigning in Northern Virginia and the aggressive Republican quest for a General Assembly majority have sent spending for the fall elections soaring to new highs, according to reports filed today with the state.

Led by Gov. James S. Gilmore III and U.S. Rep. Thomas M. Davis III, who represents Fairfax and Prince William counties, Republicans launched an extensive campaign of political giving in the weeks before Labor Day, showering GOP candidates from the Beltway to the beach with major contributions.

Davis, the top strategist in the National Republican Congressional Committee, sent $262,500 from that organization to Virginia legislative candidates in the final two weeks of August, and this year he has dispensed an additional $85,000 from his political action committee, the Virginia Victory Fund, his senior political adviser said.

"We spread it out to all competitive races," said John Hishta, Davis's veteran campaign aide. "Tom wants to see a majority after November."

With Republicans enjoying narrow control of the state Senate and near-parity with Democrats in the House of Delegates, the legislature is the state's political prize on Nov. 2, when all 140 assembly seats are on the ballot.

Sitting governors and some well-financed members of Congress such as Davis have often helped favored legislative candidates, but the sums this year--when neither presidential nor statewide candidates appear on the fall ballot--are nothing short of staggering, politicians and their aides said today.

"Mail, mail, mail!" cried state Sen. Jane H. Woods (R-Fairfax), complaining about the literature costs that she said have forced her to raise more than $345,000 in her fierce race against Democrat Leslie L. Byrne.

Woods, who counts Davis as a constituent, received his special attention, collecting $40,000 from the NRCC and $22,000 from his PAC, Hishta said. Woods reported having $164,000 on hand.

Byrne, who was turned out of Congress by Davis in 1994, reported $83,000 in cash after raising $183,000 for the year, a good chunk of it from organized-labor groups.

Those dollar figures are incomplete, in part because not all of the campaign filings were available today at the state Board of Elections. In addition, the reports that were required to be filed today don't reflect the big-dollar push that candidates in both parties will make later this month and through October.

Nevertheless, the broad dimensions of fund-raising by party leaders were fast becoming clear. Gilmore said he had collected $1.3 million through his New Majority Project PAC and had more than $419,000 of that in cash on hand for a generous eleventh-hour burst of donations.

The governor is relying on firm GOP control of the assembly to secure a lasting political and legislative legacy and has been tireless in his pursuit of the majority, mailing thousands of copies of a partisan video in an effort to generate $4 million for Republican incumbents and challengers.

Another Gilmore-controlled PAC, the Commonwealth Council, said it had raised nearly $638,000 and still had $342,000 in cash.

Davis was a double-barreled giver, using his NRCC position to help candidates who would otherwise have to compete for dollars nationally, were it not for Virginia's off-year election cycle.

For instance, Del. James H. Dillard II received $10,000 from the NRCC and $5,000 from the Davis PAC, and Scott T. Klein (R) got $10,000 from each entity in his race for an open state Senate seat in Fairfax County.

The Davis-controlled contributions were mostly $5,000 to $10,000, but some lawmakers got larger sums: Del. Jeannemarie Devolites, a Davis political protege, received $15,000 from NRCC, and Del. Michele B. McQuigg got $25,000. Both have Democratic challengers.

Virginia has no limits on political giving, and the reports filed today showed a variety of sources for candidates, depending on their leanings.

In addition to $5,000 from the Democratic Senatorial Campaign Committee, Byrne reported $2,000 from Firefighters Local 2068, $1,000 from the Food and Allied Services Trades and three gifts of up to $2,500 from the Virginia AFL-CIO.

CAPTION: DAVIS