Alleging that a new voter identification law is unconstitutional, the Democratic Party of Virginia sought an injunction in a Richmond court yesterday to block a pilot project that would require voters in 10 localities--including Fairfax and Arlington counties--to show ID cards before casting their ballots in next month's elections.

The party, joined in the suit by the Virginia Beach Democratic Committee and 12 individual plaintiffs, asked the Richmond Circuit Court to stop enforcement of the voter ID program Nov. 2 in part because it "cannot be administered fairly and uniformly" by then.

The suit also alleges that the law creating the pilot program "places an unconstitutional burden" on people's right to vote in the 10 localities by imposing requirements that do not apply to voters elsewhere in the state.

The state board of elections plans to send out 1 million voter ID cards to ensure that people can meet the requirement to show identification at the polls. Those cards are being printed now and are scheduled to be mailed about Oct. 19, said Cameron P. Quinn, the board's secretary, who is among the suit's defendants. The cards will be accompanied by a letter explaining the pilot project.

Other acceptable forms of identification under the law include voter registration cards, Social Security cards, driver's licenses, passports and military or student IDs.

The law, aimed at preventing voter fraud, passed narrowly in February along party lines. It established the experimental program in five counties and five cities totaling about 1 million registered voters. About 60 percent of the affected voters live in Fairfax County.

The program creates "a high potential for significant confusion on Election Day," said Craig K. Bieber, executive director of the Democratic Party of Virginia. He said voters are confused about which forms of identification will be acceptable, and he expressed concern that long delays at polling places could result. Some voters, especially minorities, could feel intimidated or be discouraged from voting, he said.

Republicans rejected those arguments, saying that producing an identification card has become routine these days and that the program was justified by a recent board of elections audit that showed thousands of ineligible voters on Virginia's rolls.

"We certainly want as many people to vote as possible," said Timothy Murtaugh, a spokesman for the state's Republican Party. "We just want them to do so legally." He added: "We'll take the side of clean and honest elections any day. The people of Virginia ought to be alarmed that the Democratic Party of Virginia is in court fighting to keep the pathways open for voter fraud."

The identification law was approved 21 to 19 in the Virginia Senate on a party-line vote, then passed the House of Delegates 51 to 49 when one Democrat voted for it by mistake, Bieber said. At the time, Republicans said the law was necessary because some convicted felons, mental patients and people using the names of dead voters were able to cast ballots illegally in last year's elections.

"The Republicans keep saying this is a tremendous problem, and yet they've never produced any evidence that people are voting fraudulently," Bieber said. "Their approach to this is similar to trying to kill a flea with a shotgun."

Noting that the U.S. Justice Department has approved the pilot program, Murtaugh said, "If the Democratic Party has a beef with this, they should take it up with President Clinton."

The battle over the voter ID program erupted as both parties continued to pour money and volunteers into close races for the Virginia legislature. A national group, Democrats 2000, has sent young campaign workers to help 13 candidates for the General Assembly--five of them in Northern Virginia--as part of an effort to prepare for similar campaigns in nine states next year.

"Everyone knows how crucial these Virginia elections are," said Beth Kanter, a spokeswoman for the 12-year-old program originally organized by liberal members of Congress to help elect "progressive, populist Democrats."

"They're really going to set the tone for 2000," she said.