The Maine Ethics Commission will open an investigation into the Maine Democratic Party’s disclosed spending against last year’s unsuccessful referendum to enact voter ID requirements and new limits on absentee voting.

The commission voted unanimously Wednesday to investigate the party in response to a complaint from conservative activist Alex Titcomb, who spearheaded the referendum, Question 1, alongside Rep. Laurel Libby, R-Auburn. Maine voters resoundingly defeated the ballot initiative in November, with about 64% opposing it and 36% supporting it.

Titcomb, leader of The Dinner Table PAC, argued the Maine Democratic Party qualified as a ballot question committee under state law because it received and spent more than $5,000 to oppose Question 1. The party acknowledged it spent about $250,000, but told the commission it complied with the law by filing its spending in regular campaign finance reports it submitted as a party committee under a different state law.

Titcomb replied that even if those committee reports were the proper way for the party to disclose its spending, it still did not file all required reports. The party also did not clearly designate which spending was against Question 1, Titcomb said.

Attorneys for the Maine Democratic Party said the matter comes down to the commission’s interpretation of the different statutes.

The party also received “confusing” reporting advice from commission staff on this very question, its lawyers told ethics commission executive director Jonathan Wayne. Ethics commission staff told the Sagadahoc County Democratic Committee last year that a political group “may want to consider registering” as a ballot question committee, but that it was not required, the Democrats’ attorneys said.

Ethics commissioners from both parties expressed a desire for transparency Wednesday in voting to open an investigation. It is unclear how long the probe will take or the maximum penalties the party could face if the commission determines it committed any violations.