The rallies and the speeches are over, most of the contributions have been spent, the television ads run and the pollsters done with their polling. But party officials say the campaign for Virginia governor may yet be won or lost in little rooms such as the one located on the second floor of an aging building at Baileys Crossroads.

Here about 50 workers have spent three hours a night, six nights a week, sitting on stiff metal chairs, punching the buttons on the white telephones to call thousands of registered voters in the Washington suburbs.

The callers' mission: to identify Republican voters, sway GOP-leaning undecideds, and urge both groups to the polls Tuesday.

The Republicans say they will call 500,000 Virginia voters from this and 22 other telephone banks around the state, giving gubernatorial nominee J. Marshall Coleman and his running mates a traditional technological edge that Democrats in past elections have been unable to match. Both sides agree that the GOP telephone banks have been worth 3 to 4 percentage points on past election days -- enough to make the difference in some of the close electoral triumphs of the 1970s.

But just as Democrat Charles S. Robb has made inroads into Republican money and supporters this year, his campaign is challenging the GOP's technological edge. Robb's campaign has poured about $200,000 into a get-out-the-vote operation, including five professionally run telephone banks. It is, the Democrats say, by far their best telephone effort and one they contend could match the Republicans.

"In the past, they've been able to get every identifiable Republican voter to the polls and we haven't been compeitive," said Robb in a recent interview. "This time, we are competitive."

Republicans acknowledge the Robb campaign's achievement but insist their own voter-turnout operation will triumph again on Tuesday. Anson Franklin, Coleman's campaign manager, puts this year's GOP edge at two points and says of the Democrats: "They can't match us. They probably will do more than before but they don't have a system that can keep up with ours."

The Republican system, which one operative calls "our secret weapon," will cost the Coleman campaign $250,000 to $300,000. Its key element, honed over the past decade, is its computerized voter lists.

The party buys voter registration lists from the state Board of Elections, but those lists don't include vital information such as telephone numbers and previous voting history. Nor do they include party affiliation, since Virginians don't register by party.

The party's computers collate the purchased lists with precinct workers' turnout lists. The results are printouts that tell telephone bank workers who their most likely supporters are. These final GOP sheets are so sensitive they are locked at night in special safes designed to fit their size.

Respondents who say they will vote for Coleman or his running mates are designated for a second telephone call sometime in the last 72 hours before the election, reminding them to vote.

The undecided get a form letter within days of their first call, with each letter tailored to discuss issues important to the region they live in. Northern Virginians are getting a letter from Coleman outlining proposals to solve the area's mass transit and road problems.

On election day, a final computer printout of the GOP's most favorable voters goes out to volunteers at every polling place. The poll watchers check off the voters who show up and pass on to other volunteers names and telephone numbers of those who haven't. Before evening, the no-shows are contacted again by telephone and urged to go to the polls. In the better organized precincts, those without transportation are offered rides to and from the polls.

For the first time this year, the Republicans also have used a special telephone bank, located on a floor below Coleman headquarters in Richmond, to raise campaign contributions. Using past GOP contribution lists, the telephone operation has raised pledges of slightly more than $300,000 since it began operation last June. Deducting 30 percent for overhead, Coleman finance director Charles Tyson says he still expects to make close to a $200,000 profit for the campaign.

By comparison, the Democratic telephone operation is bargain basement. While Republicans have been working the telephone banks since mid-September, the Robb callers started three weeks ago, using a streamlined system designed by campaign manager David Doak. His procedure concentrates on Democrats and undecideds from precincts with a history of Democratic or swing voting.

While Republicans use their telephone banks and direct mail to massage undecided voters, the Democrats are interested solely in identifying and getting out committed Robb voters. And while the Democrats won't reveal how many voters they expect to contact, simple multiplication based on numbers supplied by the Democrats suggests they will reach about 250,000 -- half as many as the Republicans.

To run the telephones, Doak hired National Voter Contact Inc. of Washington, one of only about three nationwide professional telephone bank operations. During the summer, the company put together its own computerized sheets, matching voter registration lists with telephone numbers.

While the Republican telephone banks rely heavily on volunteers, Robb's operation uses paid workers exclusively, because Doak believes they do a more consistent job. Workers are expected to make 35 calls an hour during the final voter-turnout calls that began this weekend.

Everything about the telephone bank set-up is designed to produce more calls. The metal chairs have no arm rests so that workers have to rest their elbows on the tables where the telephones are. "It helps force them into the phone," said Glenn Cowan of National Voter Contact.

Cowan, whose company operated telephone banks for the Carter-Mondale presidential campaign last year, said Democrats across the country are just beginning to realize how important telephone banks have been to the Republicans. He is confident the five Robb telephone banks can make a 2 to 3 point difference for the candidate.

"In the past, Democrats have treated it like a luxury they couldn't afford," he said. "But when it's a luxury, you lose elections."