The hissing sounds emanating from the dais at the D.C. Council's meeting last month were not being made by members reacting to another unwelcome proposal from Mayor Anthony A. Williams.

This time their exasperation was aimed at one of their own, Phil Mendelson (D-At Large), who was holding up the vote on a bill that would create a new D.C. housing authority. It was the last meeting of the year and the council was not willing to delay action that would return the agency, which has been in federal receivership for four years, to local control. Mendelson was ruled out of order, the question was called and the bill passed.

The D.C. Council is eager to erase the perception that it is an insignificant player in the city's governance structure. Voters reconstructed the council in the last election, retiring longtime members in favor of challengers who promised change. The current council, which marks its first birthday this month, has strived to live up to its billing as new and improved.

The council has been assertive in challenging the mayor's agenda and aggressive in helping rebuild the District's fractured infrastructure. Council members say residents and officials can expect more of the same this year as they prepare for budget negotiations with Williams (D) in the spring and take on reforming major city functions, most notably the D.C. school board.

Linda W. Cropp (D), who is starting her third year as chairman of the council, summed up the council's attitude in a recent interview: "We decided that we are going to be an equal branch of government."

The declaration was repeated by several of her colleagues and has become a mantra for this council, which makes no apologies for the public--and sometimes caustic--debates it has waged with the popular Williams during his first year in office.

For most of the 25 years of home rule, the council has been largely ignored by the executive branch and seen by residents primarily as a pork barrel for parochial needs. Williams joined the criticism during his 1998 mayoral campaign, chiding the council for being complacent while the District's finances and services disintegrated. Those days are over, say council members.

Jim Graham (D-Ward 1), a freshman member of the council, said he felt a particular sense of accountability to the voters who chose him over the incumbent who had represented the ward for 16 years.

"Each institution has to have integrity in the government," he said. "You want a vibrant council . . . [one] that not only exerts itself but is responsible for what's going on in the government."

A palpable sense of purpose has radiated from the council during the past year. Members appear better prepared for legislative sessions, hold more oversight hearings and rarely fight with each other in public. Another factor in the post-Marion Barry era of District government has emboldened the council to push its way into the forefront of the District's reform movement: a new mayor who is less adept in managing the politics of the local government.

Barry, a former council member, had long-standing relationships with many individuals who served on the council during its first two decades. He also often used his popularity with political and social activists to intimidate political foes on the council. And he was not above flattering members by dropping by their office to personally ask for their support on an important issue.

Williams controls no votes on the council; members constantly complain that he doesn't confer with them. As a result, the two branches are often at odds over political initiatives.

The council stared down Williams, the city's former chief financial officer, on his first budget last spring, adopting the largest tax cut in the city's history and shifting dollars from the mayor's priority areas to its own. In recent weeks, the council also forced the mayor to rework a plan to finance bonuses for city workers and to revisit a controversial development plan for a project in Columbia Heights.

David Catania (R-At Large), who along with Graham introduced the bill that led the Williams administration to seek concessions from the developers of the Columbia Heights project, said the council is finally coming into its own.

"I don't view conflict as a bad thing," Catania said. "I view this type of tension as constructive and positive, where you have two co-equal branches of government who are competing to lead. . . . I don't view skirmishes with the executive branch as they win or we win. It's just who is seizing the opportunity to lead? And on a lot of issues this council this year has decided to lead."

Williams has been somewhat taken aback by the level of tension, given that both he and council members "basically agree philosophically."

"Because we agree philosophically in many, many areas, that has relegated many of our differences down to the personal level," Williams said.

"This has been an interesting year for the council," he added. "The focus over the last year has been striking an institutional balance, which is good for the city. But over the next couple of years, the council will have to politically sort out among themselves their own differences. They can't be united all the time because we're all politicians. It's just not going to happen."

Members say the council is more united than ever. Part of the reason has to do with its makeup: All the members have been elected since 1990, except for Charlene Drew Jarvis (D-Ward 4), who is going into her 21st year on the council. Unlike the old-school liberals who dominated previous councils, most members of the current group describe themselves as political moderates.

The council, which for the first time is majority white, didn't spend the entire year wrestling with Williams for control of the District government. Council members have drafted and rewritten laws governing the operation of major city services. In addition to the bill reviving the housing authority, the council enacted stricter licensing laws for teenage drivers, deregulated the sale of electrical power in the city and created a registry program to alert residents to sexual offenders living near them.

While the council's chambers are rarely filled with spectators--most of the visitors are lobbyists, except during hearings on controversial bills--advocacy groups have taken note and cautiously praise the city legislature's work.

Natalie O. Ludaway, chairman of the public affairs group for the Greater Washington Board of Trade, said the council's tax cut was a "substantially positive step in improving the business climate in the District." But she cited as "troubling" the council's tendency to dabble in development matters.

The business community cringed when the council sided with residents and sought to revise plans in Columbia Heights and in Foggy Bottom, where the American Red Cross sought city bonds to build a 10-story headquarters. If developers adhere to zoning and other laws, their efforts should not be thwarted by "political" interference, she said.

Social welfare activists such as Angela M. Jones, of D.C. Action for Children, gasped last spring at the council's initial tax-cut proposal, which would have cost $431 million over three years and might have resulted in some service reductions.

Last month, Jones was cheering the council when it took on Williams's plan to use $9.9 million from the city's tobacco settlement to pay for bonuses for union government workers. D.C. Action was part of a coalition of children's and health organizations that had lobbied city officials to reserve the tobacco settlement money for anti-smoking and other health programs. The council agreed to the mayor's financing plan only after he indicated how and when he would repay the tobacco fund.

"I think, frankly, we are pleased the council is beginning to take such an active role throughout the legislative process," Jones said. She said council members are more "accessible. . . . They're asking for more citizen input, their staff is more knowledgeable about the issues, you see them more at community meetings than in past years."

"As a native Washingtonian, for the first time I'm experiencing a true democratic process going on in Washington," she added. "I would like to see less of this mayoral and council fighting, that's politics."

Later this month, the council will hold a retreat to lay out its legislative agenda for the year. Legislation is moving through the council to reform major city services. Council member Kevin P. Chavous (D-Ward 7) has introduced a bill that would change the way school board members are elected. Sharon Ambrose (D-Ward 6) is working on a proposal to create a new department to regulate the sale of alcoholic beverages and to tighten laws that have permitted bars and stores that sell liquor, beer and wine to crowd into some neighborhoods.

Catania is moving forward on a bill that would give more muscle and resources to the advisory neighborhood commissions, the elected community boards that have been criticized for being poorly run and ineffective in protecting residents' interests. Council member Jack Evans (D-Ward 2) is preparing another round of tax reforms, this time aimed at removing residents who make less than $20,000 a year from the tax rolls.

Mendelson, the freshman member who often is chastised by his colleagues for wanting to slow the pace of the council's work, said he is nonetheless happy to be a part of the new government.

"I think the council is working better than it did three to four years ago," said Mendelson, a former council staff member. He said the council must strike a delicate balance between being independent from the mayor but not being insurgent.

"If we're perceived as just throwing up obstacles and trying to thwart the mayor, we will have failed in the public eye," he said.

The majority of his colleagues would readily second that notion.