AUGUSTA — An 11th-hour legal technicality could jeopardize the use of a voter-approved election overhaul in June primaries, state elections officials said, but supporters of ranked-choice voting vowed to press forward.

Secretary of State Matt Dunlap was set to brief lawmakers on Thursday on the rollout of the system for the June 12 primaries. Instead, he surprised them by saying that an apparent conflict discovered a day earlier would sink plans for using the system this summer without a last-minute fix.

For now, he promised his office would keep on planning for a rollout even though it currently conflicts with different sections of law governing elections. “Our plan right now is to proceed on the line we’re on,” said Dunlap, adding that his office needs to print ballots for overseas voters in the coming weeks.

Meanwhile, ranked-choice voting supporters vowed to seek an injunction against Dunlap to force implementation, and called any delay an “affront to democracy.” Maine has been on track to become the first in the nation to use ranked-choice voting for a statewide primary election.

The ranked-choice system lets voters rank candidates from first to last. A candidate who wins a majority of first-place votes is declared the winner, and there are additional tallies if no one wins an outright majority. The process could take a week or more to play out.

“I think the secretary of state at every turn has attempted to obstruct the implementation of ranked-choice voting,” Committee for Ranked Choice Voting spokesman Kyle Bailey said.

Democratic Attorney General and gubernatorial candidate Janet Mills said she would submit a legislative fix and urged lawmakers to act.

“The will of the people must not be thwarted by some technicality in the law,” she said.

But that may be wishful thinking. Any legislative fix would require a two-thirds majority in each chamber, setting a high bar for supporters.

Democratic House Speaker Sara Gideon said the courts should move quickly to eliminate any uncertainty.

Mainers approved the new voting concept in a statewide referendum in November 2016 but lawmakers delayed implementation. More than 62,000 petitions were collected for the second statewide vote on June 12, when Maine voters could vote to thwart the delay.

Dunlap said lawmakers have not changed a Maine statute that says a primary winner receives a “plurality of the votes.”

Maine’s top justices last year advised lawmakers that the voter-approved law conflicts with the state’s constitution, which requires a “plurality” of votes for general elections for state office.