Republican lawmakers in Richmond, prodded by the GOP's duo on the Fairfax County Board of Supervisors, yesterday embarrassed Democrats in the Virginia House of Delegates by defeating for the second time in 72 hours legislation to expand the county's Economic Development Authority.

In a vote that reflected both the partisanship of the Democrat-controlled House and the political realignment in Fairfax, supporters fell four votes shy of the 67 votes needed to pass the local legislation enlarging the economic development authority from seven to 11 members.

The key to the 63-to-25 result, with 12 delegates not voting, was a conscious effort by House Republicans to vote as a bloc against the bill, a decision made all the easier, many said later, by a last-minute appeal from Thomas M. Davis III (Mason) and Elaine N. McConnell (Springfield), the two Republicans on the nine-member county board.

In copies of a two-page letter dated yesterday and placed on the desks of all 35 Republicans in the House, Davis and McConnell derided the authority's expansion as "nothing other than an effort of the {board's} new Democratic majority to 'pack' the membership with partisan appointees."

"We ask for your help," Davis and McConnell said in their letter. "Politically 'packing' an authority of this magnitude with partisan cheerleaders," they said, "will not improve the county's economic development policy or the prestige" of the authority.

As they did on Friday, when the same bill sponsored by freshman Sen. Emilie F. Miller (D-Fairfax) failed by a single vote, House Democrats vowed late yesterday to resuscitate the measure before the General Assembly adjourns next week. Del. C. Richard Cranwell, an influential Democrat from Southwest Virginia, said he intended to graft language expanding the authority onto one of two other bills before the session ends.

"I'm going to save everybody," said Cranwell, alluding to both sides of the partisan fracas.

Several legislators said Miller's bill was as much a victim of conflicting and confusing signals from county politicians and lobbying groups as it was that rare cause uniting Republicans from across the state.

"There were too many conflicting stories about who was or wasn't supporting it, and what the real intent was," said Del. Gladys B. Keating (D-Franconia), who managed the bill on the House floor.

"It was a mess," Keating added. "I don't care how eloquent I was, it would not have passed."

Others in Richmond said the bill was ensnared by, if not a product of, the ongoing debate in Fairfax over the county's development, which came to a head last November when Democrat Audrey Moore, an advocate of slower growth, ousted Republican and longtime development champion John F. Herrity from the board's chairmanship.

"It was a hangover from the elections," said Scott McGeary, a legislative lobbyist for a trade association of Northern Virginia builders, who monitored the unsteady progress of Miller's bill. "The thing got all caught up in partisan politics."

Meanwhile, in Fairfax, Democratic supervisors heatedly denied they were playing a political game through Miller's bill.

Board Chairman Moore called the issue "a misunderstanding," and blamed the controversy on "a small group of people who I think are stirring up a hornet's nest."

Moore said the original wording of the bill was unclear to some members of the authority and the county's Chamber of Commerce, who, believing the legislation was antibusiness and designed to remove some authority members, initially lobbied against its passage in Richmond without understanding its intent.

Fairfax County Board Vice Chairman Martha V. Pennino (D-Centreville) said it was "absurd" to believe the bill was antibusiness or designed to harm the authority. She said the legislation, which she proposed, was designed to increase minority and small business representation on the authority, which she said currently is composed mostly of major corporate representatives.

Davis said he would support the bill if it merely permitted the county to enlarge the authority, rather than making the expansion mandatory. He added he would support the legislation if each supervisor had an appointment, which he said would encourage more communication between the two government agencies.