Virginia Gov. Mark R. Warner (D), surrounded by business, school and civic leaders and other supporters of a regional transportation tax, said opponents have failed to propose any solutions to Northern Virginia's traffic congestion and instead offer only "sound bites."

"When you cut it all away, the opponents offer no solutions. They offer the status quo," Warner said at a news conference in the Arlington County Board room, where advocates for the Election Day ballot question gathered.

"If they think the money is going to come from Richmond, they're wrong," said the governor, on his fifth visit to Northern Virginia in the referendum campaign's final push. "We're going through extremely difficult challenges in Richmond right now. Where would they cut? They don't say."

Anti-tax activists say the proposed half-cent increase in the sales tax to 5 cents per dollar is unnecessary and would only persuade lawmakers in Richmond to withdraw state transportation money. They say more road and transit money for the Washington suburbs could be freed up if state government were more efficient and leaner.

"The governor is screaming very shrilly that there is no alternative," said state Sen. Ken Cuccinelli (R-Fairfax), a leading opponent of the tax. "He's been demagoguing it. . . . But there are alternatives."

Instead of raising taxes, the state should allocate more money to build roads in Northern Virginia, taking it from more rural areas that need it less, Cuccinelli said. "Where are my cuts? They're going to come from other parts of the state's transportation budget."

With four days to go before Election Day, both sides in the most intense political struggle in Virginia are sharpening their attacks on each other as they reach out to voters. Both sides say the contest is too close to call. It's now a rush to make phone calls, distribute literature, hold get-out-the-vote rallies, and air television and radio spots.

Environmental groups that also oppose a higher sales tax released a report yesterday highlighting the contributions developers have made to the pro-tax campaign.

The groups said a tax increase would benefit only real estate developers who want more roads sprawling across the suburbs.

"What you didn't see up there was the development industry," said Stewart Schwartz of the Coalition for Smarter Growth, who attended the Arlington event. "They're sensitive to the criticism that this is all about sprawl."

Groups that have endorsed the tax increase took turns stating why they believed their constituents would benefit. Public safety officials said wider roads would speed response times for fire and rescue vehicles in emergencies; business leaders said their employees would enjoy shorter commutes, and school officials said that if the tax proposal fails, parents and teachers will not find lawmakers who support another tax increase to pay for new classroom space. Proponents say the tax will raise $5 billion over 20 years.

"Some of you may be wondering, what is a nice superintendent like me doing at a rally for transportation?" said Fairfax School Superintendent Daniel A. Domenech, who at one time opposed a transportation-only measure. "If we don't show the folks in Richmond there's a willingness right here to solve our own problems, there's very little hope we can go back to them and say, let us do something for education."

About 40 percent of the projects and programs specified in the referendum legislation involve mass transit, including new rail cars and buses for Metro. Supporters hoped today their message that the referendum is not only about bigger roads would resonate in Arlington, a close-in suburb where many residents rely on on mass transit to get to work.

"This is a once-in-a-lifetime opportunity to generate millions of dollars for trains and buses," said Richard A. White, Metro's chief executive officer.

After a swing today through Hampton Roads, where a one-cent sales tax increase is on the ballot, Warner plans to return to the Washington suburbs on Monday for rallies in Manassas and Alexandria.

Anti-tax opponents have scheduled a rally this morning at Burke Lake Park in Fairfax County.

Gov. Mark Warner joined supporters of a tax increase at a news conference in Arlington, where they described how it would help transportation.The two sides in the political struggle over the transportation tax are sharpening their attacks on each other as they reach out to voters. Both sides say the contest is too close to call.