Former Alexandria mayor Charles E. Beatley is favored to win the Democratic primary tomorrow in Virginia's 8th Congressional District, but his only opponent, political newcomer Cliff Snyder, is hoping for an upset.

The winner of the Democratic primary will face Republican Rep. Stan Parris in the Nov. 4 general election.

If he succeeds in dashing Beatley's political comeback, party officials say, Snyder, who until January was as a scientist for the Army's Medical Service Corps, will likely have ended the former mayor's public career.

Voters in the 8th Congressional District, which includes Alexandria and parts of Fairfax, Prince William and Stafford counties, will go to the polls between 6 a.m. and 7 p.m.

Each candidate says he would push Congress for a stronger commitment to education and enough funding to extend the subway to Springfield. However, they differ greatly in style and priorities.

"The way Chuck Beatley has conducted the campaign has been in the worst tradition of American politics," Snyder said.

Beatley refused to debate Snyder when the Fairfax Young Democrats offered to sponsor the forum. Snyder, 30, said the former mayor "refused to let people know how he stands on issues" and "doesn't allow people to make an informed choice."

Beatley, 69, said that if "a reputable organization" had offered to host a debate, he would have accepted.

Beatley strongly criticized Snyder, who has expressed opinions on national issues, for being more interested in putting troops on the Mexican border to stop illegal immigration than in important local political issues. Snyder said the possibility of using an Army division with 15,000 soldiers to help patrol the southern border and the need for a handgun control law are issues he wants to discuss.

"I'm not going to debate that [the Mexican border]," Beatley said. "I want to talk about Metro's extension to Springfield . . . . I'd move heaven and earth to get it."

Snyder, a resident of Fairfax who earned his PhD in biology at the University of Virginia, said he is indeed interested in local issues, such as stopping the construction of a state road through the wetlands of Huntley Meadows in Fairfax and exploring the feasibility of easing the Metro stations' parking crunch by permitting only cars with more than two passengers to park.

George C. Rawlings Jr., Democratic Party chairman for the 8th District, said either candidate would have a "good shot" at Parris. But Democrats and Republicans alike say that it would take a miraculous campaign to defeat Parris, who has already raised more than $225,000 and is in his third consecutive term.

Beatley would not say how much money he has raised but said he has spent $10,000. Snyder said he has spent $9,000, 80 percent of it his own money.

"This is still a Democratic district," Rawlings said. "As long as a Democrat has enough money, he doesn't need more [than a Republican]."

Rawlings said he believed Beatley or Snyder could defeat Parris with one-third of the money used by the Republican candidate.

Democratic leaders concede that each candidate has problems to overcome. They say that Beatley has a negative image raised during his 1985 mayoral election and that Snyder has a name recognition problem.

"Some people are kind of down on Beatley," Rawlings said. "But against Parris he may be the pick."

Beatley, long a popular Alexandria figure who served 18 years on the City Council, 15 of them as mayor, was defeated in 1985 after vocally criticizing Police Chief Charles T. Strobel, who was accused of mishandling a drug investigation.

Strobel, a 28-year veteran of the police force, was cleared of any impropriety by a special state grand jury last year and then acquitted by a federal jury in April of perjury and obstruction-of-justice charges.

James P. Moran Jr., who defeated Beatley last year, criticized his opponent for raising "baseless accusations against city staff."

Beatley promised a tough fight against Parris if he wins the primary, and he said he has many supporters who are eager to work on his comeback campaign.

Snyder, an avid runner, said that if he wins tomorrow he will walk 450 miles through the district's 149 precincts to knock on doors before the fall race.