Three Maine environmental groups want a pair of federal agencies to suspend the permits they issued for the New England Clean Energy Connect project that voters rejected this month.

On Monday, the Natural Resources Council of Maine, the Sierra Club and the Appalachian Mountain Club wrote a joint letter to the U.S. Army Corps of Engineers and the federal Department of Energy asking that permits issued for the 145-mile transmission corridor through western Maine be suspended or otherwise stayed.

The letter pointed out that the Maine Department of Environmental Protection last week suspended its construction license for the project after Maine voters on Nov. 2 passed, with about 60 percent of the vote, a referendum to block the corridor that would be used to transmit power from hydroelectric dams in Quebec to the New England grid via Lewiston.

The electricity is ultimately destined for customers in Massachusetts, who are paying for the $1 billion project.

The letter from the environmental groups cites the referendum as the main reason the project’s federal permits should be suspended. It also noted the Maine DEP permit suspension and a state court ruling that invalidated a lease on a nearly 1-mile stretch of land in the middle of the planned path for the transmission corridor.

The Army Corps had issued a permit for the project under the Clean Water Act, and the Department of Energy had issued a presidential permit required because the project would cross an international border.

NECEC is being developed by a subsidiary of Central Maine Power parent company Avangrid. The developers sparked controversy when they challenged the constitutionality of the referendum in court and continued work on the project the day after the ballot measure was approved.

NECEC subsequently suspended work at the request of Gov. Janet Mills, and last week’s DEP ruling required the company to stop work unless it is granted a court injunction or a favorable ruling on its challenge to the referendum.