A sign painted on a window at a Patagonia clothing store voices opposition to Central Maine Power's proposed 145-mile transmission line to bring Canadian hydro-electric power into New England, Wednesday, Oct. 6, 2021, in Freeport, Maine. Credit: Robert F. Bukaty / AP

The battle over Maine’s $1 billion hydropower corridor continued Wednesday when the attorney general asked a court to deny a request by the project’s builder to block the Nov. 2 anti-corridor referendum that voters passed overwhelmingly.

In a 36-page filing to the Maine Business and Consumer Court in Portland, Attorney General Aaron Frey’s office argued that Avangrid Networks’ and NECEC Transmission’s claims for the preliminary injunction lack merit. Avangrid, the parent company of both Central Maine Power Co. and NECEC, the entity building the corridor, filed a lawsuit the day after the election saying the referendum was unconstitutional.

The state’s stance is notable given Gov. Janet Mills’ pro-corridor position, although the Democrat urged the corridor’s builders to stop construction last week, which they did within hours. With millions of dollars in business and hundreds of jobs at stake, CMP and its allies have a narrower path to defending the project after the Maine Department of Environmental Protection cited the referendum in suspending a key permit this week.

Frey and Assistant Attorney General Jonathan Bolton argued that the corridor builders’ request for a preliminary injunction would potentially allow the project to be finished before the lawsuit is decided, which could take a couple of years. That would go against the will of the voters.

“The estimates provided by NECEC’s own witnesses show that such an injunction would likely allow NECEC to complete or nearly complete construction of the corridor while this lawsuit remains pending,” the attorney general wrote.

Frey’s office also questioned NECEC’s arguments that delays of the project could put it at risk because it can only extend the contract to build the project one year, until August 2025, arguing that it could be possible to extend that completion date in an arrangement with Massachusetts, which is financing the expansion of the regional power grid.

Avangrid and NECEC also are arguing that they have “vested rights” because they spent about $450 million on the project build-out so far in good faith. The attorney general’s filing said NECEC “made a high-risk business decision” by continuing to build despite the lawsuit and referendum, and “is now asking the court to protect it from the foreseeable consequences.”

NECEC continued construction the day after the referendum vote, prompting outcry from corridor opponents. The company complied with Mills’ request to stop last week, but wrote Mills a strongly worded response the same day saying it would stop benefit payments including electric rate relief and educational funding. In its filing for the injunction the company said it has paid out $18 million of its promised $250 million in benefits.

The letter, signed by Avangrid Networks CEO Catherine Stempien, NECEC Transmission CEO Thorn Dickinson and CMP CEO Joseph Purington ended with a terse, “and, by the way, we are not quitting on NECEC.”

The Portland court is expected to rule on the preliminary injunction in mid-December.

Correction: An earlier version of this story contained a typographical error in a citation from the state’s filing in the corridor case.

Lori Valigra, investigative reporter for the environment, holds an M.S. in journalism from Boston University. She was a Knight journalism fellow at M.I.T. and has extensive international reporting experience...