Charging that Alexandria faces "an uncertain and potentially grim future" unless it changes leaders, Republican City Councilman Carlyle C. (Connie) Ring Jr. said yesterday that he will challenge Democratic Mayor James P. Moran Jr. in the city's May election.

Ring's announcement, which portrayed Moran as an advocate of high taxes and wasteful spending, ended weeks of uncertainty regarding both the mayor's race and the contest for all six seats on the City Council. Ring has spent several months considering whether to oppose Moran or seek his fourth three-year term on the council.

Republican Party officials said privately that if Ring had stayed in the council race, the GOP probably would not have fielded a candidate against Moran, who defeated a 15-year incumbent in 1985.

While party leaders cheered Ring's decision, they are left with another problem: The GOP now has no incumbents running for the council. All four Democratic council members are seeking reelection.

Both Ring and Moran predicted yesterday that this year's mayoral election will be less personal and more issue-oriented than Moran's emotional battle against Mayor Charles E. Beatley three years ago.

"Jim Moran is a charming guy. He's a personal friend of mine," Ring said. "But he is vulnerable {politically} because people are sensing that the city is not going in the direction they think it should go . . . . Our taxes and tax rate are the highest in the state. Our per capita expenditures are the highest in the state."

"I can't think of anyone that would provide better competition than Connie Ring, because of his intelligence, his knowledge of the city and his willingness to work hard," Moran said. "Our biggest difference is in personality and attitude toward decision-making.

"Connie is more reliant on the letter of the law as it is already established. I'm more inclined to challenge the law if it binds our ability to represent our constituents."

Moran and his fellow Democrats begin the election season with definite advantages: a ticket loaded with incumbents, an electorate that leans toward Democrats in local elections and a party structure that is largely unified. Alexandria Democratic Chairman Lonnie Rich said yesterday that because several potential Democratic council contenders have opted out of the race, the party may be able to avoid a primary election scheduled for March 8.

"I don't think there's any doubt as to what the outcome of the mayor's race will be -- Jim Moran will win," Rich said. "If {Ring} has any hope of doing well he has to run as an individual, separate from the Republican council ticket. It's made up of people who are basically inexperienced or fringe candidates."

But Alexandria GOP Vice Chairman Michael Holm said that the party's council ticket will include several candidates who have sought office before. "I think Connie is a strong leader for the ticket," Holm said. "And I am confident that we will come up with a strong slate of people."

"I like being an underdog," Ring said. "The best chance for me to win is for {the Democrats} to go to sleep. And I think they're asleep."

Ring's announcement yesterday painted a relatively bleak picture of Alexandria under Moran, far from the quaint image associated with the city's Old Town historic district.

"Our streets are choked with traffic," he said. "Drug peddlers have taken over some of our neighborhoods. And the middle class, the blue-collar group that is the backbone of this community, is moving out. Alexandria is becoming a city of the very rich and the very poor."

Ring said that to combat those problems the city should cut back on spending and taxes. Although the city's real estate tax rate has gone down about 5 percent in the last five years, skyrocketing land values have pushed most individual tax bills up.

Ring voted against last year's city budget because he said its tax cut did not go far enough. The 1989 budget will come before the City Council in the middle of the campaign.

Moran said that he, too, believes taxes are too high, but voted for last year's budget "because we decided that having well-paid teachers that would stay in the city was more important" than cutting taxes.

Ring did not raise an issue that recently provoked a strong disagreement with Moran: the city's plans to open a public clinic that would dispense contraceptives to minors. Moran favored dispensing contraceptives at the clinic and Ring opposed it.

"Connie is far too clever to let it be an issue," Moran said. "He knows he already has a lock on all the anti-clinic voters. He will now attempt to deemphasize it."

The mayor's post, which pays $12,500, is classified as a part-time position. Ring is a corporate lawyer and Moran is a stockbroker.