More than two dozen neighborhood activists, previously unsuccessful contenders and political novices will vie for nine Montgomery County Council seats, making this one of the most contested elections in recent memory.

Seven council members are seeking reelection, and each will face a challenger in either the primary or general election. In addition, five people have entered the race to replace County Executive Douglas M. Duncan (D), whose decision to step down after 12 years in office, coupled with possible changes on the council, has the potential to significantly alter the political landscape of the county.

"I think this is going to be a year unlike any we've seen," said Amy Presley, a community activist from Clarksburg.

As of yesterday's deadline for filing candidacy papers, 26 people are vying for the $79,721-a-year part-time council jobs. With the majority of the candidates running as Democrats, the Sept. 12 primary will serve as the county's main political event.

The primary is shaping up to be a referendum on growth. As in the county executive race, voter concern about the pace of growth has dominated the debate. Voter angst over traffic congestion has also topped the agenda.

"I think voters are most concerned about development in the county, whether it is being overseen properly and whether or not we are growing in a manner that best serves the county," said Roger Berliner (D), a Potomac lawyer who is running against incumbent Howard A. Denis (R) to represent the 1st District, which covers Potomac and Bethesda.

Council member Steven A. Silverman's candidacy for county executive and council member Tom Perez's quest to become the state's next attorney general guarantee at least two new faces on the council.

The most contested race will be for one of the council's four at-large seats. Three incumbents -- Nancy Floreen, Michael L. Subin and George L. Leventhal, all Democrats -- are seeking reelection. But they have 10 challengers, including Maryland National Organization for Women President Duchy Trachtenberg (D).

Political observers say the incumbents could be facing tough reelection battles. Four -- Floreen, Subin, Phil Andrews (D-Gaithersburg-Rockville) and Marilyn Praisner (D-Eastern County) -- failed to capture endorsement from the county's influential teachers union.

"There are attractive new candidates out there, so the incumbents have every right to be concerned, but they also have incredible advantages," said former council member Bruce Adams (D).

Though competitive, this race has not yet matched the contentious tone of the 2002 council election.

In that election, the most recent, Duncan breezed to a third term, aligning himself with a group of candidates who supported his transportation initiatives, primarily the intercounty connector.

The End Gridlock slate, as it was known, included all the at-large members of the council: Silverman, Subin, Floreen and Leventhal, who is now council president.

But many residents believe traffic has worsened -- a fact that challengers are trying to use to their advantage.

"Definitely, the End Gridlock slate from last time is really being put under the microscope," said Gail Ewing (D), a former council member.

Several challengers have criticized the council for eliminating formulas in 2003 for determining whether certain communities were too overwhelmed by traffic to sustain new housing.

"The End Gridlock slate sort of defined the problem away rather than solved the problem," said at-large candidate Marc Elrich (D), a county schoolteacher.

Still, many of the challengers have not offered specific proposals for alleviating traffic, other than managing the county's growth better. Some, such as at-large candidate Bill Jacobs (D), a computer analyst from Olney, have gone as far as promising to place building moratoriums in areas that are traffic-clogged. Others are sounding a more moderate tone.

School board member Valerie Ervin (D), who is running for Perez's District 5 seat, said the county has to continue to grow, but it must be managed better.

"I think this is a very polarizing conversation that people have to be on one side or the other," she said. "I don't want that kind of conversation."

The End Gridlock council members say they increased the impact tax that developers must pay. Floreen also said the council has made a significant investment in road and transit improvements, including a recent decision to fund several road improvements until the state agrees to pay for them. Of the End Gridlock slate, she said: "That's nothing we define ourselves by. I try to define myself by action."

Denis will try to hold on to his District 1 seat against Berliner. Four years ago, he narrowly defeated Trachtenburg, who is now in the at-large race.

In the District 2 Democratic primary, which encompasses most of northern Montgomery, Michael Knapp will face Sharon Dooley, a health-care consultant.

The District 3 Democratic primary will be a rematch between Rockville City Council member Robert E. Dorsey and incumbent Andrews, who has been the most adamant slow-growth voice on the council. Dorsey tried to grab the seat, which represents Rockville and Gaithersburg, four years ago with Duncan's backing.

Three candidates, including two Republicans, will try to nab the District 4 seat held by Praisner. In District 5, which covers Silver Spring, Ervin will face Hans Riemer (D), political director for Rock the Vote, in the Democratic primary.