AUGUSTA — The Maine Ethics Commission is continuing its efforts to shield the identity of two out-of-state political consulting firms involved in the $1 billion Central Maine Power transmission corridor project – even as it prepares to take legal action against the firms.

The commission’s lawyer, Assistant Attorney General Jonathan Bolton, is expected to file a lawsuit soon in Superior Court in an effort to enforce a subpoena for records from the firms, which appear to be based in California and Virginia.

But the commission, in a discussion at a July 30 meeting, decided to give the firms advance notice of the suit so they can file simultaneous motions asking the court to seal the case from public view while a judge decides whether to enforce the commission’s subpoenas.

The commission is trying to determine what involvement the firms have had with Stop the Corridor, a nonprofit, limited liability corporation that has been campaigning against the transmission line corridor project through western Maine being developed by CMP and Hydro-Quebec.

At issue is whether Stop the Corridor should have registered as a political action committee or a ballot question committee under state campaign finance disclosure laws, which would require it to file reports showing its donations and expenditures.

To do that the commission’s investigators want access to the financial records of the still unnamed political consultants, who have not complied with the state’s subpoenas.

Jonathan Wayne, the commission’s executive director, said Stop the Corridor asked that the commission keep names in the subpoena confidential. The laws that govern the commission provide confidentiality for “sensitive political or campaign information” belonging to an organization or “financial information not normally available to the public.”

Stop the Corridor has contributed more than $85,000 of in-kind support to No CMP Corridor, a  political action committee formed in 2019 to oppose the powerline project. No CMP Corridor has received more than half of the $315,000 it has raised from Mainers for Local Power, another PAC formed in opposition to the powerline.

Mainers for Local Power, in turn, is being bankrolled by Florida-based NextEra Energy Resources LLC, which has donated $6.7 million to the PAC since it formed in 2019. NextEra is an energy supplier whose bottom line could be hurt if the transmission line is built, to bring renewable energy from Quebec to New England.

Supporting the project is Clean Energy Matters, another PAC that has also been largely funded by corporate interests, including Hydro-Quebec and the parent company of Central Maine Power Co. – the Spanish energy giant Iberdrola. That PAC has spent more than $25 million on its efforts since forming in 2019.

Newell Augur, an attorney for Clean Energy Matters, has opposed the request for confidentiality, saying it does not meet the requirements of state law.

“Moreover, we believe any continuing grant of confidentiality to these two entities – that are simultaneously refusing to comply with duly executed subpoenas by the Commission – is a noticeable departure from prior investigations and will create a dangerous precedent,” Augur said in a letter to the commission.

The Portland Press Herald/Maine Sunday Telegram has asked the commission that it be notified when the unidentified consultants are alerted to the court filing, so that it has the opportunity to submit arguments to the court on behalf of public disclosure.

Wayne says the commission is striving to comply with the state law that protects the confidentiality of certain business records and sensitive political or campaign information.

“This law helps our Commission obtain information to judge non-compliance with the state’s campaign finance laws,” Wayne said in an email to Sig Schutz, an attorney who represents the Press Herald on open meetings and open records issues. “Ultimately, this confidentiality provision leads to greater information being available to the public about campaign finance non-compliance, once the Commission is able to finish its investigation and report its results publicly.”

But Schutz disputes the notion that keeping such information confidential improves the efficiency of an investigation.

“Not only is (the) premise questionable, but the fairness of the process is at stake as well,” Schutz said. “In any event it’s not a policy issue for the Commission to decide in the end. If they file in court then all, or at minimum substantially all, of their filing must be public.”

Spending on the transmission corridor issue is likely to intensify soon, as Mainers will vote in November on a statewide ballot question seeking to block the project.

Supporters and opponents of the project already have spent more than $15 million. More than $13 million of that has been spent by the two political action committees largely bankrolled by CMP and Hydro-Quebec.

The question will ask: “Do you want to ban the construction of high-impact electric transmission lines in the Upper Kennebec Region and to require the Legislature to approve all other such projects anywhere in Maine, both retroactively to 2020, and to require the Legislature, retroactively to 2014, to approve by a two-thirds vote such projects using public land?”

In July, the state’s Supreme Judicial Court ruled the ballot question could go forward. The court rejected arguments from the plaintiff in the case, a state lawmaker, that the question should be divided into three separate questions on the ballot.