PORTLAND, Maine (AP) — Maine’s highest court is scheduled to hear arguments on Wednesday about the future of a citizens’ campaign to block a much-debated hydropower project.

The arguments concern the New England Clean Energy Connect, which calls for construction of a 145-mile (233-kilometer) high-voltage power line from Mount Beattie Township on the Canadian border to the regional power grid in Lewiston, Maine. The Maine Public Utilities Commission granted the project a key certificate it needed to move forward, but petitioners gathered enough signatures to put the approval up for a statewide vote.

Central Maine Power has proposed the transmission line. Avangrid Networks, CMP’s parent, sued the state of Maine with a claim the citizens’ initiative was unconstitutional and the vote should be barred.

Opponents of the project have long claimed it would harm Maine wilderness. Supporters have said it would help stabilize electricity rates and support sustainable energy development.