State appellate judges yesterday grilled a city attorney who argued that the Bloomberg administration adhered to the democratic process when it gained approval for a $16 million redesign of Washington Square Park.

The city is appealing a state judge’s ruling in July that halted renovation of the historic 10-acre park, which would include erecting a perimeter fence and moving the central fountain 22 feet to align it with the Washington Square arch.

The original plaintiffs in the case are Greenwich Village residents who have long opposed the city’s plans for the park. The residents, led by the lead plaintiff, Jonathan Greenberg, have said the changes are too dramatic and would ruin the character of a park known for its daily variety of street performers and frequent political protests. Their case against city has a much narrower focus.

They contend that the Department of Parks and Recreation misled Community Board 2 about the extent of the renovations by failing to disclose that the new design would reduce the size of the paved central plaza by more than a fifth. The plaintiffs allege the department agreed to a maximum reduction of 10% and that a larger reduction would inhibit usable space and could deter the park’s famous street performers. The city says its plans would add needed grass to a square now dominated by pavement in disrepair.

A central issue is whether the community board has any substantive role in the review and approval process for the park renovation. The Bloomberg administration is contending that, by and large, it does not. “It’s only advisory, at most,” the city’s attorney, Deborah Brenner, said after the hearing, echoing the argument she made in court.

The plaintiffs’ attorney, Arlene Boop, argued that the city’s position “really vitiates the entire role of the community board.”

Before the justices, Ms. Brenner contended that regardless of the community board’s power, the city made its plans well known in numerous public hearings, meetings, and presentations. “The democratic process did work in this case,” she told the court. She later added: “It’s not as though this plan was shoved through.”

Although the justices frequently interrupted attorneys for both sides with questions, they seemed to more heavily scrutinize the city’s argument that the Parks Department was forthcoming with the community about its plans. “They failed to accurately disclose the extent of the reduction. That’s where they say the democratic process failed,” Justice Luis Gonzalez said to Ms. Brenner, who acknowledged the city did not discuss the extent of the reduction.

The case could also pits two City Council members, including the speaker, Christine Quinn, against the administration. The justices called into question a letter written last year by Ms. Quinn and Council Member Alan Gerson to the parks commissioner, Adrian Benepe. The letter, submitted by the plaintiffs as evidence, states that an agreement was reached that the redesign would not reduce the plaza by more than 10%. Ms. Brenner said the letter was “never signed or acknowledged by the Parks Department” and that the City Council had no role in the process.

A decision on the case could take months, and until then, the renovation cannot begin. The city has asked that the case be expedited.