Gov. Mark R. Warner's decision to cut $858 million from state spending is stirring concern among fellow proponents of the Northern Virginia transportation tax that a sharp reduction in government services will dampen support for the tax increase on the Nov. 5 ballot.

Strategists on both sides of the referendum agreed that Warner's budget cuts, announced last week in a statewide TV address, will not by themselves determine the outcome of the regional ballot question. Voters in nine Northern Virginia jurisdictions will decide whether to raise the sales tax rate by a half-percentage point to 5 percent, generating an estimated $5 billion over 20 years for local transportation and mass transit projects.

However, both camps agree that, for the purposes of the Nov. 5 vote, Warner and other proponents might have slightly more to lose politically in the wake of his far-reaching plan to reduce state spending. In a suburban region already unsettled by a roving sniper, a stagnant economy and potential war with Iraq, the budget cuts constitute one more tricky Election Day variable that could further depress voter turnout, strategists said.

"It cuts both ways," said state Del. John A. "Jack" Rollison III (R-Prince William), a leading advocate of the sales tax increase. "The cuts certainly drive home our argument that you can't go to the general fund for the $5 billion you need for transportation projects."

"The other side is: It really frightens people to see government contracting," Rollison added. "Right now, people don't want to make major decisions about their lives. They're holding back."

Warner, a Democrat who has built a bipartisan coalition of officials and community groups to support the referendum, acknowledged that his budget cuts could work against proponents. "I know you can make the argument . . . people will be less likely to [vote yes] because of economic uncertainty," Warner said.

But Warner also argued that because the cuts entail hard choices about spending in tight times, they could actually end up helping the tax proposal and two other ballot questions authorizing roughly $1 billion in bonds for state colleges and parkland acquisition.

"This notion, somehow, that there's a lot of available resources in Richmond that could be dedicated to these billions of dollars of needs if we could simply do a better job of reprioritizing -- there may be some in the anti-tax camp who will still make that claim, but I don't know how they're going to make it with a straight face," Warner said.

"Making these long-term investments -- whether it's transportation, higher education, parks -- those are the kind of long-term investments we're going to need to make if Virginia is going to be the place to get the 21st century right," Warner added.

Referendum opponents, many of them Republicans who are at odds anyway with the Democratic governor, complain that proponents have it backward: that government should start with the kind of cost-savings and efficiencies that Warner unveiled and make higher taxes -- even by referendum -- a last resort.

Opponents also said the budget cuts reinforce their argument that government generally is a poor steward of public funds -- whether it's a state government that has grown beyond its means, as Warner and others said, or a new regional transportation authority that would have control over billions in tax dollars. On Friday, Warner named audit committees to oversee spending of any new sales tax revenue in Northern Virginia and Hampton Roads, which is also holding a regional referendum on a transportation tax.

"People see the budget crisis and ask themselves: If the government spent itself into a mess to the point they now have to make significant cuts, why should we give up more money?" said state Del. L. Scott Lingamfelter (R-Prince William), a referendum opponent.

"They don't trust the government with more money because they don't believe the government has reformed itself," Lingamfelter said.

As a candidate last year, Warner promised voters a wholesale restructuring of state government, but since taking office in January, he and the Republican-led General Assembly faced immediate financial problems, including a $3.8 billion shortfall that was quickly followed by another that experts say is fast approaching $2 billion.

The governor's cuts affect many facets of state spending, notably the consumer-oriented Department of Motor Vehicles, which will curtail all Wednesday service and close 12 service centers permanently, and the state government workforce, which will lose more than 1,800 employees.

Other spending areas will be exempt, at least for now, Warner announced. Direct state aid to K-12 education and Medicaid -- two politically sensitive items -- as well as the State Police and sheriff departments involved in the hunt for the Washington area sniper were untouched. In a gesture to transportation tax critics who are skeptical about the management of the Virginia Department of Transportation, Warner also exempted VDOT's road-building, maintenance and mass transit programs from all cuts.

Some of the fiercest opponents of the tax said the budget cuts underscored the misplaced priorities of an administration already advocating a flawed ballot question.

"At a time when the state is cutting many essential services, it appears to us particularly inappropriate to proceed with sales tax increases," said Stewart Schwartz, head of a slow-growth coalition that opposes the referendum.

"In effect, a powerful developer and business lobby has succeeded in moving transportation, particularly highways, to the head of the line at the expense of university education, health care and the environment," Schwartz said.

John G. Milliken, a former state transportation secretary who chairs the pro-tax Citizens for Better Transportation, said it was possible that voter suspicions about excessive government spending might be stirred by Warner's budget cuts.

But a more likely scenario, Milliken argued, would be for Northern Virginia voters to "think it through another half-step and understand that Richmond is not going to address the problem and say, 'I've got to take control of it myself.' "

"The referendum is a mosaic for voters," Milliken said. With the budget cuts, "here's yet another thing that gets into their thinking."

Sen. John Warner (R-Va.) and Virginia Gov. Mark R. Warner (D) confer at a meeting of Washington Gas employees about the tax.