ANNAPOLIS -- In this season of Anne Arundel County politics, the Republican Party, buoyed by gains in Republican voter registration, a taxpayers revolt and anti-incumbency sentiment against the all-Democratic County Council, is running what many say is its first full slate of credible candidates in years.

As a result, the races for County Council seats have taken on an unmistakably and unusually partisan tone less than two weeks before the Nov. 6 general election.

Nowhere is the partisan rivalry more apparent than in District 5, where two newcomers are vying to succeed outgoing council member Carole B. Baker. The race between Republican Diane Evans, 41, and Democrat Linda Gilligan, 38, is widely considered to be the most hotly contested council race, partly because the district, which stretches from the Broadneck Peninsula to Severna Park, is the only one in which the two parties are nearly equal in terms of registration.

Evans, a child-support enforcement officer for the County Circuit Court, is a former legislative assistant to county executive candidate Robert R. Neall who espouses fiscal conservatism. She says the local government would be able to save money if it reduced the size of its work force and hired private companies to provide some of the services now performed by county personnel, such as recycling.

For her part, Gilligan, the sister-in-law of County Council member Michael F. Gilligan, resists the label of liberal. A former budget officer for Univeristy of Maryland hospital who holds an MBA, Gilligan said she is equipped to find ways to make the county government more cost-effective. While she is not as critical as Evans of the administration's purported penchant for building fancy parks, she says she believes it is time for the county to turn its attention to more basic concerns, such as maintaining school buildings.

Three incumbents are not seeking reelection this year, leaving those seats open in the general election. Of the four remaining incumbents, only District 4 council member David G. Boschert (D-Crownsville) is unchallenged.

The winners will face a gloomy financial outlook and continuing concerns about ways to manage and protect the environment.

In District 2, which includes the Glen Burnie area, Republican Ernest C. Michaelson, 55, and Democrat Edward Middlebrooks, 44, are sparring over which of them has the credentials to lead the county's 424,000 residents through difficult economic times.

Michaelson, who heads his own environmental consulting firm, said he would cut costs by having the county perform preventive maintenance on water treatment plants rather than wait for costly emergency repairs.

Middlebrooks, a lawyer, has focused his campaign on jump-starting a stalled urban renewal project for downtown Glen Burnie. He has advocated a joint venture between government and private industry to build a "festival arts center" on five acres of county-owned land. He also says that homeowners' tax bills could be reduced if the county took over from the state the process for assigning property values.

In the contest for the District 1 seat being vacated by Democratic county executive candidate Theodore J. Sophocleus, Republican candidate Gerald P. Starr, 49, a financial administrator, is also promising to be "a budget watchdog" for the council. Starr is the only candidate for local office who has endorsed a property tax limitation measure that will appear on the November ballot. He said he would try to raise the occupancy tax on hotel rooms as a way to compensate for the lost revenue.

But in a district where Democrats outnumber Republicans by a ratio of nearly 3 to 1, Starr is given little chance of winning. He is running against George F. Bachman, who gave up his council seat after 18 years to run for county executive in 1982.

Of the three Democratic incumbents facing challengers, council chairman Virginia P. Clagett (D-West River) and Maureen Lamb (D-Annapolis) are believed to be the most vulnerable, largely because of Republican registration gains in their districts. However, most observers expect both to win reelection.

Clagett, 47, has served on the council for 16 years. During that time, she has led a fight to preserve the farmland that makes up a large share of her district, and has become known as the council's staunchest environmentalist and one of the county's most popular politicians.

Her Republican opponent, John J. Klocko III, 33, a lawyer residing in Crofton, has accused Clagett of guiding the council through a period of unprecedented spending increases and ignoring the will of her constituents. Klocko says that if he is elected, he would sponsor legislation limiting the period of service for council members to three terms.

Lamb, 67, who has served on the council for eight years, is being challenged by Glenwood Gibbs, 62, a retired CIA analyst and former member of the county Board of Appeals. Gibbs has tried to appeal to voters by criticizing Lamb's vote for the $18 million Quiet Waters Park near Annapolis and her support of growth limits in downtown Parole that allow 16-story buildings.

In District 3, four-term incumbent Edward C. "Buddy" Ahern Jr. (D-Pasadena) is challenged by Republican Carl Holland, 47, a liquor salesman who lost to Ahern in the general election four years ago. Although some observers had believed that Ahern, 51, might be defeated in the Democratic primary after he lost several important endorsements, he defeated his four opponents easily and is now regarded as a shoo-in for reelection.