The U.S. Secretary of Energy, Jennifer M. Granholm took to Twitter to state that she hopes Mainers vote "No" on Question 1 next Tuesday. Credit: Lisa Leutner / AP

U.S. Secretary of Energy Jennifer Granholm on Thursday encouraged Mainers to vote no in next week’s referendum aiming to block the Central Maine Power corridor, citing the project’s clean-energy benefits for New England.

It is notable because it is rare for Cabinet members to weigh in directly on a state referendum. Mainers will vote Tuesday on a ballot question aiming to block the construction of the $1 billion corridor, a 145-mile transmission line that would bring hydropower from Canada to connect with New England’s power grid in Lewiston.

In a series of tweets from her official account Thursday afternoon, Granholm said she hoped Mainers voted no on Question 1, highlighting the benefits of reduced emissions and cheaper energy from the increased use of hydropower.

The U.S. Department of Energy issued a key permit for the corridor in January, during the final days of former President Donald Trump’s term, finding the project was in the public interest. It also concluded the transmission line would not have a significant effect on the environment, but environmental groups sued the agency in March, arguing a more thorough review was needed.

The ballot question aims to block the corridor’s construction by banning transmission lines in the Upper Kennebec region and retroactively requiring the Legislature to approve a permit for the project. The yes side appears to have an advantage going into Election Day, with a poll released Thursday showing 49 percent of respondents planned to vote yes, with 15 percent undecided.

Granholm, the former Democratic governor of Michigan, was nominated by President Joe Biden and sworn in as energy secretary in February. Both of Maine’s senators voted in favor of confirming her.