Montgomery County Council member Neal Potter greeted more than 200 supporters at a campaign kickoff yesterday, and assured doubters that his challenge to County Executive Sidney Kramer is much more than a symbolic protest.

Potter opened headquarters in Rockville and held the first news conference of his barely month-old bid for county executive to sound the theme that four years of a Kramer administration have meant overdevelopment, traffic congestion, pollution and high taxes.

And in a move sure to win political support from some parts of the county, Potter said he favors a "postponement" in construction of a light rail line between Bethesda and Silver Spring. Potter voted with the council majority last year to approve construction of the controversial trolley, but said he thinks for now the county should find more economical solutions to traffic, such as improving bus service.

Potter's announcement was hailed by Bethesda residents who have battled the project. "Now we will support him," said Anthony F. Czajkowski, a member of the Greater Bethesda-Chevy Chase Coalition, who attended the news conference.

Kramer, noting that Potter had been a backer of the trolley, said Potter's stance was a prime example of the "inconsistencies" between "what Neal says and what Neal does."

Potter's record on growth and development, the depth of his interest in being county executive and the viability of his campaign are questions that confronted him yesterday and which promise to provide fodder for his opponents.

Potter late last year agreed to run for reelection to the council on a slate with Kramer. Then he decided to retire from politics. Potter admits that when he filed just hours before the deadline July 2 to run for county executive, he was not sure whether he could conduct an adequate campaign.

But today, he said, his campaign is very real -- "not a gesture, not a protest but an effort to give the voters a real choice." Potter said he has raised $25,000 and 200 people have volunteered to help in his campaign. Dick Crane, press spokesman for State's Attorney Andrew Sonner, said he is taking 15 days of annual leave to manage Potter's campaign. Sonner has been an outspoken critic of Kramer and once considered running for county executive.

Kramer has raised more than $200,000, his campaign organization has been in place for months and he has the support of a majority of elected officials. Indeed, two of Potter's closest allies on the council, Bruce T. Adams and Isiah Leggett, refused Potter's appeal to jump ship. The two are running on a ticket with Kramer, and Adams said part of the reason is his belief that Kramer is better qualified to be executive.

However, Potter said he has the power of issues such as the concern of citizens over the pace and amount of growth. He criticized Kramer's support of major development in downtown Silver Spring, his opposition to a special tax on development, his encouragement of economic development and the reliance of his campaign on donations from development interests.

Kramer countered that "the decisions that have been made on land use -- zoning, subdivisions, master plans -- are the product of the County Council." He said Potter in his 20 years on the council often has voted in favor of the plans that produced the growth.

Kramer maintained that he has been consistent in his promise to voters to provide for planned and controlled growth.

Researcher Sandra Lee contributed to this report.