A Pepco employee works on a Maryland power line after the derecho storm in 2012. Pepco could have a new owner under a deal now pending before D.C. and Maryland regulators. (Matt McClain for The Washington Post)

Four D.C. Council members, as well as neighborhood commissioners and local activists, called on the mayor Tuesday to take a stand on a looming energy merger that they say will hurt city jobs and the environment.

D.C. regulators will decide soon whether to sign off on the $6.8 billion purchase of Washington-area utility company Pepco by Chicago-based energy giant Exelon.

A key factor, opponents say, is that Exelon has valued Pepco at $2.5 billion more than the net book value of the company’s assets.

Four council members and more than half of the city’s 42 local advisory neighborhood commissioners say that although the deal would deliver a significant windfall to Pepco shareholders, it also could pressure the company to raise rates — and gives little to no long-term benefits to Pepco customers.

Council member Mary M. Cheh (D-Ward 3) described Exelon, the largest owner of nuclear power plants in the country, as a “distant, mammoth corporation” focused on selling energy and “at odds with the progressive environmental agenda of the District of Columbia.”

“If Exelon takes over Pepco, what will happen is, we will face higher rates. We will face loss of jobs,” Cheh said during a news conference on the steps of District government headquarters. “We will face a lack of accountability, because although they will have an office somewhere, I guess, we will be subject to control by a distant corporation that has little or no concern for us.”

Cheh’s call to oppose the merger was backed by council members Charles Allen (D-Ward 6), David Grosso (I-At Large) and Elissa Silverman (I-At Large).

Myra Oppel, a spokeswoman for Pepco Holdings, said Tuesday that Exelon has pledged to hold off on job cuts “at the utility level for two years after the merger.” But, she said, “there hasn’t been any determination” about whether a similar pledge will apply to rate increases.

The District’s Public Services Commission will determine this month whether the merger is allowed to proceed, based on whether it serves the public interest. D.C. Mayor Muriel E. Bowser (D) and the D.C. Council have no official role in the decision.

Local political leaders and activists said Tuesday that the mayor’s voice is important as the commission hears comments and opinions from the public.

“We are here today to call on Mayor Muriel Bowser, who has been effectively silent on this issue that affects every D.C. resident and business, to hear the voices of her constituents and come out against the merger before it’s too late,” said Judi Jones, an advisory neighborhood commissioner from Ward 4.

The mayor did not respond to queries about the merger Tuesday. A spokesman for her office said that the deal “is still under review by the mayor’s legal team.”

“As the last jurisdiction to review the merger, the Bowser administration is committed to negotiating a resolution that best serves the interests of District residents and ratepayers,” said Mike Czin, the mayor’s communications director.

Cheh, who has opposed the mayor on several other issues, noted after the news conference that one of Bowser’s senior advisers, Beverly Perry, is a former Pepco vice president. Cheh suggested that the mayor’s administration may be compromised on the issue.

“Pepco is insinuated in this government in many, many ways,” she said. “So it wouldn’t be surprising to me that you hear a lot of silence.”

Czin said that Perry “recused herself from this issue at the beginning of the administration.”