Mayor Vincent C. Gray has nominated a former utility consumer advocate to sit on the influential Public Service Commission, setting up a potential confrontation with powerful Pepco, which opposes the choice.

For 18 years, attorney Elizabeth Noel was the People’s Counsel, a $155,653 city position in which she represented consumers’ interests against local utilities. In recent years, Noel opposed Pepco’s rate-hike proposals and questioned the utility’s objections to burying power lines when the practice could result in safer, more reliable service.

“Pepco should not be permitted to ‘scare’ regulators, policymakers and consumers away from a serious conversation about burying power lines by saying over and over again that burying cables costs $8 million per mile,” she wrote in a letter to the editor in The Washington Post in 2008.

Pepco said her previous activism as people’s counsel disqualifies her from serving on the three-member commission, which regulates the city’s electric, gas and phone utilities. “Ms. Noel is qualified on the subject matter but her work experience creates an irreconcilable conflict of interest,” according to a statement Thursday from utility spokesman Clay Anderson.

He noted that Noel worked for the people’s counsel office for 12 years before heading the agency, and that she was the “counsel of record” in 90 percent of the agency’s cases against utilities. She would have to recuse herself from a majority of the commission’s decisions, Anderson said.

But the Gray administration appears to be standing firm on Noel’s nomination, which was introduced in July. The D.C. Council, which returns to session Tuesday after its summer recess, would have to approve the nomination.

Linda Wharton Boyd, a spokeswoman for Gray (D), said Attorney General Irvin B. Nathan, general counsel Brian Flowers and Ron Collins, director of Boards and Commissions, all looked into Pepco’s conflict-of-interest claim. They found that Noel would be required to recuse herself from participating in some cases, but that eventually the board would handle cases in which she had not participated, Wharton Boyd said.

. . . The concerns voiced by the utilities are fair in the short term, but not an issue in the long run,” she said.

The Office of the Attorney General found 22 cases pending before the commission that were filed before Noel left her post as people’s council. In seven of those instances, the office said, any conflict could be resolved by separating more recent complaints that had been attached to an existing case.

Lobbyists for Pepco argue that cases can stretch from a few years to a decade, so her recusals could be long-term in a post that pays $146,457 annually.

However, some council members and Gray supporters question privately the benefit of pushing Noel’s nomination, especially because the administration has been hobbled by controversial personnel decisions. Most recently, Andi Pringle, Gray’s new deputy chief of staff, resigned after she acknowledged voting in last year’s Democratic primary though she lived in Maryland.

Noel, who has the support of some local labor unions that supported Gray’s election last year, did not return requests for comment. She is popular among local consumers who rallied around her when then-mayor Adrian M. Fenty decided against reappointing her as the people’s counsel in 2009.

Joslyn Williams, president of the Metropolitan Washington Council, AFL-CIO, dismissed rumblings that Noel’s nomination is a favor to his labor union. “This is about consumers,’’ he said. “Our members are consumers, too, who had to suffer through the hurricane (without electricity).”

Council member Yvette Alexander (D-Ward 7), chairman of the Committee on Public Services and Consumer Affairs, said council rules dictate that she hold a hearing on the nomination as early as this week.

Though Alexander is a Gray ally, she said she remains neutral about Noel’s nominations. “I’ll respect the mayor’s nomination,” she said. “I’ll hold a hearing. I want to hear the pros and cons of her nomination.”

Alexander said she has not heard any objections from other utilities but that Pepco has lobbied her against Noel’s nomination.

Council member Phil Mendelson (D-At Large), a member of the committee, said Pepco’s concerns are giving him pause but that he has the “highest regard” for Noel. “She was an effective consumer advocate,” he said.

Mendelson also said utilities could object to some of the decisions she makes if she is confirmed. “If utilities feel strongly enough . . . they could litigate,” he said.

First elected in 1998, Mendelson said he could not recall a mayor nominating a former people’s counsel to the commission.

Currently, the commission is composed of former council member Betty Ann Kane as chairman and attorney Lori “Missy” Murphy Lee as a member. Noel would replace Richard E. Morgan, who has served two terms and formerly worked on staff at the commission, the U.S. Environmental Protection Agency and the U.S. Department of Energy.