A sign in protest of Central Maine Power's hydropower transmission corridor displayed at a camp near the site of the first pole in West Forks on Tuesday, Feb. 9, 2021. Credit: Linda Coan O'Kresik / BDN

AUGUSTA, Maine — A dueling set of energy companies spent another $7 million in the fight over the Central Maine Power corridor in the first three months of 2021 as a referendum on the transmission line is likely to go to voters this November.

The new flush of money follows more than $19 million in political spending around the corridor in 2020, when a ballot question aiming to rescind its permit was declared unconstitutional. Secretary of State Shenna Bellows’ Office announced in February that opponents of the 145-mile transmission line secured enough signatures for another ballot question this year.

The new referendum aims to change state law to require legislative approval for any transmission project on public lands, though it too may face legal challenges as corridor opponents hope to apply it retroactively.

The Legislature could also be forced to vote on the project’s leases independently after a judge ruled last month that the state must determine whether the project, which aims to bring hydropower from Canada, will substantially alter the land that it crosses, though that will depend on a determination from the Maine Bureau of Parks and Lands.

The massive spending for and against the corridor highlights its importance to energy companies on both sides. The pro-corridor spending so far this year was led by Clean Energy Matters, which spent more than $4.6 million, primarily funding media buys and voter outreach. The committee received its funding from a company formed last year by Central Maine Power’s parent company, Avangrid, to oversee the corridor project.

Mainers for Local Power, a committee opposing the corridor that largely funded signature-gathering efforts for the November referendum, spent another $2.1 million over the same period. Slightly more than half of that spending — about $1.1 million — went toward canvassing and signature gathering efforts in January.

The group also began working on ads around the time the ballot initiative was approved. It received most of its first quarter funding from NextEra Energy, a Florida-based energy company that operates the oil-fired Wyman Station power plant in Yarmouth and renewable projects here, with smaller contributions from Calpine and Vistra, which operate natural gas plants in Maine.

Hydro-Quebec, the Canadian energy company behind the transmission project, also spent more than $800,000, though that was largely in service of paying down its political committee’s previous debts. Maine lawmakers are considering legislation this year that would ban foreign companies, such as Hydro-Quebec, from spending to affect Maine elections.