The Arkansas Supreme Court ruled on Thursday that an abortion-rights amendment was ineligible for the November ballot, agreeing with state officials that organizers of the effort had failed to submit all of the required paperwork.

The measure appeared all but set to proceed last month when organizers announced they had submitted more than 101,000 signatures in favor of it, well above the minimum 90,704 signatures required to put a constitutional amendment on the ballot.

But John Thurston, the secretary of state, rejected the petition outright, saying that organizers had failed to correctly submit a sworn statement confirming that paid canvassers had been instructed on how to collect signatures.

The organization behind the measure, Arkansans for Limited Government, sued to revive the petition and force state officials to count the signatures. While the court required a count of the signatures collected by unpaid volunteers, that total — 87,675 — came in short, Mr. Thurston’s office said.

The majority opinion came on the day of the deadline for state officials to finalize the November ballot. Three of the seven justices — Chief Justice John Dan Kemp, along with Justices Karen R. Baker and Courtney Hudson — dissented.

Of the nearly dozen states where organizers were looking to voters to restore some abortion rights after the Supreme Court overturned Roe v. Wade, Arkansas presented perhaps the most difficult environment.

Its deeply conservative and evangelical base of voters makes it one of the few states where a majority of voters do not support some abortion access. And anti-abortion groups, as well as allies of Gov. Sarah Huckabee Sanders, a Republican, rallied in opposition to the proposed amendment.

In a bid to appeal to centrists and libertarians in the state, Arkansans for Limited Government crafted a ballot initiative that would not go as far as some other states. Current law only allows for abortions if a pregnant woman’s life is at risk due to a medical emergency; the proposal would have allowed for abortions up to 18 weeks after fertilization and additional exceptions for incest, rape and when a fetus would not survive outside of the womb.

This is a developing story. Check back for updates.