WASHINGTON (Reuters) - The U.S. Supreme Court on Monday left in place a lower court’s ruling that barred private citizens from suing Ohio for allegedly impeding their ability to vote by requiring ballot forms to be filled out perfectly.

The justices declined to review the ruling that dismissed claims by Ohio’s Democratic Party and homeless rights groups that the state’s “perfect form” law, which invalidates ballots for even minor errors, deprived thousands of people of their right to vote, violating the federal Voting Rights Act. Such suits must be filed by the federal government, not private citizens, that court held.

The Northeast Ohio Coalition for the Homeless in Cleveland, the Columbus Coalition for the Homeless and the state Democratic Party challenged a pair of 2014 laws.

Those laws required county election boards to reject absentee and provisional ballots unless voters had properly and completely filled out the forms that come with the ballots, including with their name, address, birth date and signature.

Ballots were rejected even if the voter’s identity could be determined despite the errors, the plaintiffs told the justices in legal papers. Some were thrown out for omitting zip codes, using cursive writing instead of print, or writing in the current date instead of a birth date, they said, disenfranchising thousands of voters in recent elections, especially minorities.

The plaintiffs claimed the laws were unconstitutional, violating voters’ rights to due process and equal protection under the law. They also alleged the laws violated a provision of the Voting Rights Act that outlaws voter disqualification for errors that are “not material” to determining voter eligibility.

Last September the Cincinnati-based 6th U.S. Circuit Court of Appeals found the laws to be mostly legal, striking down only the requirement that absentee voters accurately provide their full address and birth date.

The court also said the Voting Rights Act provision at issue could only be enforced by the U.S. attorney general, and lawsuits by private parties were barred.