TALLAHASSEE — A group of anti-abortion advocates are trying to force Florida’s abortion amendment off the ballot this November or void any votes cast for it, citing a report from the DeSantis administration that said there was “widespread” fraud in the petition gathering for the effort.

A lawsuit filed Wednesday in the 9th Judicial Circuit argues that the sponsors behind Amendment 4 failed to meet the required signature threshold to get on the ballot when that alleged fraud is considered. The anti-abortion plaintiffs are being represented by former Florida Supreme Court Justice Alan Lawson.

Amendment 4 proposes protecting abortion access until viability, about 24 weeks of pregnancy, and would undo the state’s ban on most abortions after six weeks of pregnancy. Gov. Ron DeSantis has vowed to defeat the initiative.

To get the amendment on the ballot, the sponsor group Floridians Protecting Freedom gathered nearly a million verified signatures from people across the state, about 100,000 signatures above the baseline qualifying requirement. The Department of State certified the amendment to appear on the ballot early this year.

But last week, the department released a report after reviewing petitions that local supervisors had already deemed valid, an unprecedented move, according to elections supervisors. In the report, the state’s Office of Election Crimes & Security argued that 16.4% of the petitions should have never been validated.

Using that number, the lawsuit argues that the amendment only got 833,521 valid petitions statewide, falling short of the 891,523 requirement.

The Yes on 4 campaign has denied any wrongdoing, and has previously said the state’s report is “nothing more than dishonest distractions and desperate attempts to silence voters.” It said the report is part of a larger attempt by the state to defeat the amendment.

A deadline in state law to challenge the validity of amendment signatures has long since passed, and the state did not make any challenge during that period. Hundreds of thousands of voters across the state have already voted using mail ballots, which have been printed to include the Amendment 4 question.

The lawsuit says a long list of county elections officials “failed to conduct a sufficient review before verifying Amendment 4′s petition forms and signatures.”

Along with reaching at least 891,523 valid petitions statewide, the campaign also needed to get a required number of valid signatures in at least half of Florida’s congressional districts. The lawsuit argues that the amendment sponsors failed to do that if the fraud reported by the state is factored in.

The state’s review of validated petition signatures has prompted outcry from critics, who see it as part of a pattern of the state targeting the abortion amendment. In recent months, DeSantis has leaned on the power of state government to combat Amendment 4.

His state health agency put up a website opposing the amendment and launched ads pointing people to those websites. And the state health department threatened TV stations with prosecution if they don’t stop running certain pro-Amendment 4 political advertisements.

The state’s report included sweeping generalizations about the petition drive without providing data to back them up, including saying that county elections supervisors referred “an unusually high volume of complaints” to the state without providing a comparison to the volume of complaints to any other petition drive.

A petition drive financed a couple of years ago by the casino giant Las Vegas Sands had nearly two-thirds of all petitions rejected by county elections offices — a much higher rejection rate than for this year’s abortion amendment. But the state didn’t put out a comparable report on the casino drive.

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