The campaign to be the Republican nominee for Virginia lieutenant governor has become a surprisingly close race between two former Democrats.

With more than half of the delegates selected for a state nominating convention, the man who was considered the party's front-runner -- born-again Guy Farley of Warrenton -- now is believed to be trailing state Sen. Herbert Bateman of Newport News who, like Farley, is a former conservative Democrat.

Sen. Nathan H. Miller of Harrisonburg, who is claiming to be the only true Republican in the race, is generally considered to be far behind both men in the unofficial tallies.

But state Republican Party leaders say that the contest for the party's 3,382 convention delegates, who will choose the GOP nominees in Virginia Beach early in June, still is much too close to call.

"If you went to every Republican at the shad planking [last week's annual political gathering], you would have gotten a different version of the counts and of what was happening," says state Republican spokesman Neil Cotiaux. "It's a horse race."

By contrast, state Attorney General J. Marshall Coleman and former Fairfax Del. Wyatt Durrette will go to the convention as unchallenged candidates for govenor and attorney general.

While each of the three men's campaign headquarters claims and edge in the lieutenant governor's race, precise figures are unavailable because delegates are not required to declare their allegience publicly until the convention balloting begins. Even so, party leaders who have been closely monitoring local party meetings now give a slight lead to Bateman.

"I feel very comfortable where we are, but I'm not going to pick up and drink beer until June 6," says Randy Hinaman, Bateman's campaign manager. "I would be surprised if anyone, including Bateman, takes it on the first ballot."

Although Democrats have a reputation for the state's most intense political infighting, animosities among the three participants have made this Republican contest a lively one. Party insiders says that Miller, a boyish, 37-year-old, resents Bateman, 52, as a latecomer to the party who deliberately undercut his support with the so-called "Main Street crowd" of conservative Republican contributors.

What's more, both Miller and Farley are said to be troubled by reports that Gov. John N. Dalton and former Gov. Mills E. Goodwin secretary are working for Bateman Neither man has announced his support, but Bateman's forces gleefully are letting it be known their man is the governor's choice.

Party regulars also say the supporters of both Miller and Bateman are holding fast against Faqrley because are holding fast against Farley because they think his ties to the fundamentalist Christian right, and especially to television evangelist Jerry Falwell, could jeopardize Coleman's candidacy.

Bateman's and Miller's backers accuse Farley, 48, of packing meetings with born-again Christians. And someone -- no one will say who -- is sending delegates copies of news stories detailing Farley's association with Falwell, and Farley's divorce 10 years ago.

While some consider Falwell's support an undeniable political blessing for Farley, a statewide poll taken last fall reportedly rated the Lynchburg preacher as having the most negative image of any public figure in the state.

Some religious leaders are skeptical of claims that Farley, who has appealed directly to more than 100 clergmen, will win or lose the nomination on the basis of his religious support.

"I really don't know how great this church factor is," Carl Bieber, a Farley supporter who is minister of education at Virginia Beach's Tabernacle Baptist Church. "I tell folks, 'We're in everything.' I take church people to a [political] meeting because that's my circle of influence. If I were a lawyer, I'd bring lawyers."

Whatever Faldwell's impact, the scramble for delegates goes on unabated, with tactics some have called questionable.

In a mass meeting last week in rural Fauquier County, where Farley is chairman of the county Republican committee, scores of Miller's supporters stalked out in anger after a Farley maneuver that dropped most of the county's old-line Republicans in favor of the newer Farley supporters.

"All these years we've had different candidates, but we've worked together," grouse Jean Hume, a Miller backer. "They've brought bitterness to the party."

A similar Farley move in suburban Richmond a few weeks ago brought William Kuehl, a Miller strategist, to his feet decrying "political deals."

Farley seems to have locked up most of the 400-plus Fairfax delegation, as well as Fauquier and Loudoun counties and others father downstate. He also is planning a stiff challenge on Bateman's home turf next month in the remaining Tidewater meetings. Although Farley's support has been centered in Northern Virginia, many say his ties to fundamentalist ministers, and a recent near-endorsement from Falwell, could provide him with a political wild card.

Miller apparently is looking for a convention showdown between Bateman and Farley that will allow him to emerge as an upset winner, as Sen. A. Joe Canada of Virginia Beach did at the state GOP convention four years ago.