HELENA — A former Montana Democratic Party chairman appears to be laying the groundwork for a possible challenge to the secretary of state’s certification of the Green Party for the ballot in this year’s state elections.

Jim Larson filed a public records request with Secretary of State Corey Stapleton’s office and election officials in four counties for the individual voter information and copies of the signatures the Green Party submitted in its petition to qualify as a party in Montana.

Stapleton certified the Green Party for the first time as a political party in Montana on March 12, the deadline for candidates to file for office. Green Party officials put out a call for candidates that same day, and a half-dozen people filed under its banner for races for the U.S. Senate, House and a handful of legislative seats.

The politically left party could siphon votes from state Democratic candidates in an election year where Democratic U.S. Sen. Jon Tester is seeking a third term in office.

Larson’s letter was submitted on March 15 with a request for a response within four days. Stapleton went public with the request Monday in a tweet that read “Democrat superdelegate Jim Larson is challenging Green Party qualification signatures in Missoula, Helena, Billings and Great Falls.”

“We are working with the clerks of the four counties being challenged, and helping all parties get the information they are seeking as quickly as practical,” Stapleton said in a written statement to The Associated Press.

State Director of Elections and Voter Services Dana Corson said Larson’s request was fulfilled on March 19, except for the copies of voter signatures.

“The FOIAs are challenging for the clerks, and we have had some signatures that could not be verified, which could ultimately be removed,” Corson said.

Stapleton’s office verified 7,386 voter signatures out of the 10,160 signatures submitted by the Green Party.

To qualify for political party ballot access by petition, a party must submit at least 5,000 signatures by registered voters from at least 34 state House districts.

Larson was the state party chairman until last year and a superdelegate — meaning he didn’t have to follow the state’s primary results when voting for a presidential nominee — to the Democratic National Convention in 2016.

Neither Montana Democratic Party or Green Party officials returned calls for comment.