A judge is giving the Maine Department of the Secretary of State a month to gather new evidence and further investigate the validity of signatures backing a referendum on transgender athletes in school sports.

The office must issue a new determination of validity within 30 days, Superior Court Justice Deborah Cashman ruled Friday.

The ruling comes after a group of Maine residents argued that the controversial referendum did not gather enough valid signatures to qualify for the ballot. In a lawsuit last month, they argued that there were problems with at least 7,900 signatures that Secretary of State Shenna Bellows had verified.

The Office of the Maine Attorney General, which is representing Bellows, said many of the arguments put forward by the residents should be rejected but conceded that up to 3,014 signatures that Bellows’ office initially found to be valid should be invalidated.

The referendum, which is set to appear before voters in November, would require schools to maintain separate bathrooms and locker rooms for use by students based on the sex they were assigned at birth.

It would also require public school students to play on teams matching their sex as it appears on their birth certificates. Girls could participate on a boys team if no female team is available to them in a given sport.

The residents challenging the referendum claim there were multiple issues with the signatures and the process by which they were gathered, including that circulators left papers unattended — a violation of state law, they argue in the suit. They also pointed to suspicious-looking signatures, claiming that several appeared to be in the same handwriting.

The challengers also found duplicate signatures Bellows’ office failed to catch, Assistant Attorney General Jonathan Bolton said in a filing.

A spokesperson for Bellows’ office said Friday that it will announce its next steps in the validation process sometime in the coming week.

Protect Girls’ Sports in Maine, the group behind the referendum question, has argued that Bellows’ certification of the referendum was valid and should be sustained. In a written statement Friday, the group said there are still enough valid signatures for the question to make the ballot.

“We are confident in the skill and dedication of our petition circulators and are confident their work will pass the Secretary’s further review,” the group said.

An attorney for the plaintiffs in the lawsuit did not respond to requests for comment Friday afternoon.

The Campaign for Free and Fair Schools, a group that opposes the referendum, said it considers Friday’s ruling “a significant victory.”

“It leaves the proposed ballot question hanging on by a thread,” said David Farmer, the group’s campaign manager, citing Bellows’ earlier concession that more than 3,000 additional signatures were invalid.

The question of transgender participation in school sports has become a major issue, both nationally and in Maine. Early into his second term, President Donald Trump clashed with Gov. Janet Mills over Maine’s policy of allowing students to play on teams that align with their gender identity.