He also accused the city attorney's office of aiding Daly by providing the legal direction by which the supervisor could exploit his power as acting mayor -- traditionally a ceremonial role -- to fill vacancies on the PUC behind the backs of Brown, who was away on a trade mission, and other administration officials.

The fact that Daly consulted a deputy city attorney before he acted made the city attorney's office just as culpable, Brown said, accusing the unnamed lawyer of "apparently (writing) the road map for the purpose of filling vacancies on the PUC.''

Brown's comments, part of his push to persuade the supervisors to reject Daly's appointment of environmentalist Adam Werbach, drew a sharp retort from City Attorney Dennis Herrera, who said his deputies had acted professionally in the matter and done nothing more than provide legal advice to a client.

"For Mayor Brown or any other elected official to call their ethics and integrity into question is below the dignity of the office of any elected official,'' Herrera said.

For Brown to prevail, at least eight of the 11 supervisors would have to agree to shelve the appointment. As of Wednesday, however, he did not have the votes to do that. The full board is scheduled to address the matter next week.

"This is not about Willie Lewis Brown Jr. This is about the office of mayor,'' Brown said in unscripted remarks that lasted 40 minutes. "It is far beyond the simple process of who did the appointment. It is whether or not you and your board would sanction such conduct that is a road down which you do not want to go.''

Daly, the District 6 supervisor who represents the Tenderloin, South of Market, north Mission and surrounding neighborhoods, also had named architect Robin Chiang to the commission during his one-day shift as acting mayor Oct. 22. But Herrera, in an opinion issued Monday, said that appointment was invalid because Brown already had filled the slot with his own pick, Andrew Lee, a former Brown aide and son of one of the mayor's volunteer fund-raisers.

Daly's appointments, Brown said, "were made by a person who was supposed to be operating in a ceremonial capacity. They were made under cover of darkness.''

Without naming names, Brown said the audacious use of the powers of acting mayor "clearly is a conspiracy to, in one manner or another, move away from the traditions, the rules, the customs and the conduct that has been the hallmark of this city, long before I became mayor of this city.''

Brown suggested that the city attorney's office should have immediately informed the mayor's staff about the plan Daly was hatching so the appointments could have been scuttled. As it was, Brown revoked Daly's acting mayor designation, but it was too late. PUC commissioners, once appointed, only can be removed for cause. However, the Board of Supervisors can reject an appointment within 30 days after it has been made. That's what Brown is now hoping for now.

Herrera, who sat silently in the front row of the hearing room while the mayor spoke, had his public say after Brown left the Rules Committee hearing. Like Brown, Herrera was out of the country when the event occurred, in his case vacationing in Mexico. But he came to the quick defense of his attorneys, saying they had acted properly. Breaking Daly's confidence when he asked for advice on what powers he had as acting mayor would have violated attorney- client privilege, Herrera said.

He also told Supervisors Tony Hall and Matt Gonzalez, who serve on the Rules Committee, "You might not like, the mayor might not like, other officials might not like -- from a policy perspective -- what Supervisor Daly did or did not do. It is unprecedented here in San Francisco; it might violate rules of comity and tradition. But the law is clear: He was legally entitled to do what he did whether you agree with it or not.''

The most dramatic moment came when Hall, who chairs the Rules Committee, called Werbach to the podium after the mayor's remarks and asked him three times in a row whether he would voluntarily give up his commission assignment.

Each time, Werbach, the former president of the Sierra Club and a nationally known environmentalist, answered, "Mr. Chairman, I have no intention to resign.''

Later, Hall pressed him further, asking him whether he felt the way he got his appointment was ethical.

"The process makes me deeply uncomfortable,'' Werbach conceded, though he nevertheless stood firm in his resolve to serve on the Public Utilities Commission, which oversees the city-run, but regionally important, Hetch Hetchy water and power system.

Hall's response: "You're the victim of a rather selfish, a rather underhanded process.'' And for that reason he said he would vote to reject Werbach outright when his name gets to the full board.

Daly did not attend the hearing to hear the mayor speak in person. But a few hours later, at a different hearing on an unrelated subject, he again defended his actions saying that as acting mayor he was not beholden to Brown -- the twice-elected mayor -- but to the people of San Francisco, who deserve commissioners he deemed qualified.

"I'm an activist," Daly said. "I had an opportunity, and I took it.''

Gonzalez, the board president who is running for mayor, said that while he wasn't pleased with the process, he was with the result. He plans to vote in favor of Werbach.

"The spirit of the (City) Charter is violated when a mayor appoints somebody based on political patronage who doesn't have experience,'' Gonzalez said. He was referring, in particular to Brown's PUC appointee Lee, the son of the Brown political backer.

What it is: A city agency with 1,854 employees and an annual budget of $514.5 million that is governed by a five-member commission appointed by the mayor.

Responsibility: Operates the Hetch Hetchy water and power and San Francisco sewer and street-lighting systems.

Meetings: The five-member SFPUC commission generally meets twice monthly on the second and fourth Tuesday of each month.

Commissioner pay: $100 a month.

Future: The SFPUC is gearing up for a $3.6 billion upgrade of the Hetch Hetchy aqueduct, which brings water from the Sierra Nevada and regional watersheds to 2.4 million Bay Area customers.

E-mail the writer@rgordon@sfchronicle.com

This article appeared on page A - 15 of the San Francisco Chronicle