AUGUSTA — A supporter of a proposal to create a consumer-owned electric utility is suing to stop a separate popular vote that could stymie the effort by restricting long-term debt needed to buy out the existing utilities.

The lawsuit filed Monday asks a judge to reverse the secretary of state’s certification of petitions allowing the debt referendum to appear on the November ballot alongside one to create a new utility.

The secretary of state certified 68,807 signatures were valid, surpassing the threshold for a statewide vote by 1,125 signatures. But the lawsuit contends at least 3,200 approved signatures were invalid.

Secretary of State Shenna Bellows declined to comment Wednesday.

No Blank Checks, which is pressing for voter approval of long-term debts, dubbed the legal action a “frivolous” attempt to prevent voters from weighing in.

“These lawsuits and partisan political games are just a taste of what we would be in for if Pine Tree Power got control of our electric grid,” Willy Ritch, executive director of No Blank Checks, said in a statement Wednesday.

The lawsuit was brought by Bill Dunn, an electric utility consultant from Yarmouth who is part of Our Power, the group leading effort to create a new utility.

Supporters of a consumer-owned utility say poor performance and high electric rates warrant shuttering Central Maine Power and Versant Power and replacing them with an new entity called Pine Tree Power.

No Blank Checks contends it would cost $13 billion to buy out the existing utilities – negating any anticipated savings. Its referendum would require voter approval for debts exceeding $1 billion to buy out the privately owned utilities.

Both proposals would have to first be considered by state lawmakers. They would go to voters in November if lawmakers declined to adopt the proposals.

The Maine Legislature approved a proposal in 2021 to buy out CMP and Versant and replace them with Pine Tree Power.

Democratic Gov. Janet Mills vetoed the bill, saying that the utilities’ performance was “abysmal” but that the proposal was “deeply flawed.”