The Conservation Law Foundation, a Boston environmental advocacy organization, weighed in Tuesday against a ballot measure to replace Central Maine Power and Versant with a publicly owned utility, saying it’s “not the answer” to Maine’s power company failings.

In a posting on CLF’s website, senior attorney Phelps Turner said the two investor-owned utilities “have performance, reliability and customer service problems” that customers are, “understandably, fed up with.”

“However, voting yes on the referendum to create Pine Tree Power is not the answer,” Turner said, referring to the name of the proposed new utility.

Question 3 on the Nov. 7 ballot “provides no certainty that this quasi-public utility would solve the myriad of problems we’ve come to expect from CMP and Versant – especially as it would operate within the same regulatory framework as these current utility companies,” he said.

The foundation’s stance differs from two other longstanding environmental groups – the Sierra Club and the Natural Resources Council of Maine – who both support the controversial initiative.

Turner raised three potential problems with a publicly owned utility. If passed, Pine Tree Power will face a “protracted and litigious acquisition and transition process” that would take up time, resources and effort that would otherwise be needed to invest in transmission and delivery of electricity, he said.

The cost of a transition from the two investor-owned utilities to Pine Tree Power could otherwise fund upgrades and operational changes that Question 3 backers and opponents agree are critical to a clean energy future, Turner said.

And, he said, an elected board of seven members that would govern the new utility “runs the real risk of partisan influence and paralysis.”

Backers of Pine Tree Power said in response that they’re proud of endorsements by the Natural Resources Council of Maine, Maine State Nurses Association, Sierra Club, Maine Youth for Climate Justice, Maine Climate Action Now and other groups.

And it cited an endorsement by environmentalist Bill McKibben, who said a victory for Question 3 “would be a huge step toward dealing with the climate crisis and a model for other states.”

Former state Rep. Seth Berry, a backer of Pine Tree Power, criticized CLF’s approach, calling it the result of “deep family ties.” The general counsel for CMP’s parent company, Avangrid, is Scott Mahoney, brother of Sean Mahoney, CLF’s executive vice president.

“Today’s announcement is not news,” Berry said. “There are deep family ties between CMP and CLF. CLF has consistently put Massachusetts values over Maine people, from lobsters to the CMP corridor.”

Berry cited the brothers in CLF’s opposition to the Northern Pass, a 192-mile transmission line proposed by Eversource to deliver hydropower-sourced electricity from Canada through New Hampshire, and CLF’s backing of the New England Clean Energy Connect project advanced by CMP.

“CLF led the opposition to Canada’s mega hydropower when it would have come through New Hampshire, calling it dirty,” said Berry, former chair of the Legislature’s Joint Standing Committee on Energy, Utilities, and Technology. “They supported it when it came through Maine.”

Spokesman Jake O’Neill said CLF “carefully weighed the Pine Tree Power proposal and evaluated it based only on the facts.”

“Personal relationships never have a bearing on the positions we take,” he said in an email.

Jon Breed, a spokesman for CMP, said the utility is “happy to engage in the public debate” about Pine Tree Power, “but we won’t entertain personal attacks on the integrity of our employees or their family members.”

The CLF urged Maine officials to enforce and strengthen the Utility Accountability Law passed in 2022, suggested Gov. Janet Mills convene an advisory group to speed new clean energy projects to connect to the grid affordably, and to overhaul and reduce the costs that utilities can charge. It also said the Legislature should establish a consumer advisory panel to participate in decision-making at the Public Utilities Commission to improve transparency into the utilities’ operations and their decisions.

Backers of Pine Tree Power say a publicly owned and operated utility will keep Mainers’ money close to home. CMP and Avangrid are part of Iberdrola, a Spanish energy giant. Versant is a subsidiary of Enmax Corp., a Calgary, Canada, energy company. Supporters also say Pine Tree Power, as a nonprofit, would pay lower interest rates when tapping capital markets to upgrade the grid for greater electrification intended to combat climate change.