Virginia's House of Delegates, ignoring opposition from conservative Fairfax County Republicans, today overwhelmingly approved a 4 percent tax on retail gasoline sales in Northern Virginia to fund the Metro transit system.

The bill, the first Metro tax measure to clear the House since 1976, goes to the State Senate where supporters are optimistic for its chances of approval.

They cautioned, however, that the bill's fate remains closely tied to Gov. John N. Dalton's troubled plan for a smaller tax increase on gasoline that would be applied statewide.

Dalton's proposal for a four-cent-a-gallon increase in the state gasoline tax remains locked in a hostile House committee, and chances for passage of a compromise version were said to be improving, according to many legislators.

At today's prices, the 4 percent tax approved by the House today would add almost five cents to the price of a gallon of gasoline. Dalton's tax would increase the cost of a gallon of gasoline by four cents, increasing the current nine-cent-a-gallon state tax to 13 cents.

The Dalton bill received another rough reception from the House Finance Committee at a three-hour public hearing this afternoon. But there were indications that political pressure from the governor and the legislative leadership may yet convince committee members to override their chairman and support a two-cent-per-gallon compromise measure.

"It's still hard to tell what's going to come out," said Del. Warren G. Stambaugh (D-Arlington), chief sponsor of the regional gasoline tax bill that passed today. "I think my bill can pass the Senate provided we can all get our act together in Northern Virginia."

The Northern Virginia delegation clearly was not together today when Stambaugh's bill came up for consideration.

The delegation split over the issue of where the estimated $22 to $37 million raised annually through the tax increase should go. Fairfax County legislators have generally argued the money should be funneled to Metro through each locality so that local officials can maintain some control over expenditures, while Stambaugh and others say the money should go directly to the Northern Virginia Transportation Commission and then to Metro.

Del. Robert E. Harris and fellow Fairfax Republicans said they were under the impression Stambaugh would ask to delay action on his bill until the Dalton bill was acted on by the Finance Committee. Stambaugh had pledged to ask for a delay at a delegation meeting two days ago.

But citing "changed circumstances" that he would not reveal publicly, Stambaugh called for a vote today. That led Harris and Republicans Lawrence D. Pratt, John H. Rust, Jr. and Warren E. Barry to each offer an amendment to the bill.

Harris's amendment would have required the localities each to hold a referendum before imposing the gasoline tax Rust's called for the money raised to be funneled through the local governments, while Pratt's stipulation that 50 percent of money to fund Metro's operating costs must come from fares.

Each was defeated in rapid-fire voice votes by most Democrats, joined by some Northern Virginian Republicans. Barry's amendment, which allows localities to lower the tax should the Metro's cost decrease or gasoline prices rise steeply, passed after Stambaugh stated he had no objection.

The House then approved the Stambaugh bill by 78 to 16, with Barry, Harris and Pratt the only Northern Virginians voting against it.

Harris charged afterward that Fairfax County would be cheated by the bill. "What it amounts to is the county will be providing over 60 percent of the revenues without control over it and getting back less than 45 percent of the benefits," said Harris.

But Del. James H. Dillard, who along with fellow Fairfax Republicans Rust, Vincent F. Callahan Jr. and Martin H. Perper voted for the bill, argued that the Stambaugh bill properly shifted the burden of paying for Metro from local property taxes to a gasoline tax.

"I happen to think that's a much fairer way to raise the money and I'm extremely upset that some of my fellow Republicans didn't go along," said Dillard.

One Democrat who opposed the bill, Del. Samuel Glasscock of Suffolk, said he supported Metro but warned some lawmakers were supporting the bill only as a means to sabotage Dalton's four-cent tax proposal. The prevailing theory here is that, having already voted for their own tax increase bill, Northern Virginians will feel constrained to voted against the Dalton plan. As one lawmaker put it, "Who wants to put two taxes on your people in the same year?"

Later in the day, others said that a key legislator with close ties to the House leadership was threatening a move to scrap the Stambaugh bill unless the Northern Virginians agreed to support at least a two-cent-per-gallon statewide tax. They said that threat and the uncertainty over if and when the Dalton proposal would emerge from committee, led Stambaugh and his supporters to speed up their timetable and seek immediate passage of his bill.

"We decided we'd better not wait any longer," said one Northern Virginian.

The Dalton bill, sponsored by Callahan, got its long-awaited public hearing today. Reading from a script prepared in the governor's office, Callahan again emphasized Dalton's argument that without increased tax revenues, Virginia's highways system could suffer long term damage.

Callahan emphasized that rural secondary roads would be most hurt by the state Highway Department's projected budget crunch and omitted any mention of Metro. The transit system would receive $21 million in state construction funds over the next two years under Dalton's proposal.

He then presented a dozen spokesmen from powerful state groups such as the Virginia Retail Merchants Association, Virginia Municipal League, Fairfax County Chamber of Commerce, Virginia Coal Association and Virginia State Dairymen's Association -- each of which endorsed at least some increase in the state gasoline tax.

But the momentum switched when committee members began to grill State Highway Commissioner Harold King.

Led by committee chairman Archibald A. Campbell, an adamant foe of the gasoline tax proposal, members questioned everything from the veracity of the Highway Department's revenue projections, to the number of restrooms on Interstate 95 between Richmond and the North Carolina border.