Opponents of a Utah initiative to legalize medical marijuana for a broad list of patients are suing to stop it, hoping to block the lieutenant governor from putting the measure on November’s ballot.

The group, Drug Safe Utah, noted that, if passed, the measure would violate federal law, which prohibits marijuana possession — despite 30 U.S. states allowing use of the plant for medical purposes and eight others legalizing possession by adults 21 and older.

The group is asking the 3rd District Court to prevent Lt. Gov. Spencer Cox from putting the ballot proposal before voters.

“Legalization would leave in its wake an ocean of human lives shattered by addiction,” the complaint reads, “and a mountain of additional costs to be borne by Utah’s taxpayers and families.”

The lawsuit, filed Thursday, marks the latest escalation in the run-up to Utah’s most contentious ballot initiative.

Gov. Gary Herbert, the Utah Medical Association, the LDS Church and a slew of socially conservative organizations have come out against the measure. Opponents are also working with the U.S. Drug Enforcement Administration.

“Plaintiffs bring this suit to prevent the harm to Utah’s safety as well as the health of their children and grandchildren, from legalization of marijuana in violation of federal law and the federal and Utah constitutions,” the suit continues.

The group alleges that if voters passed the measure, state employees would be “aiding and abetting” violation of federal law by approving permits for growers and dispensaries as required by the initiative.

In response to the lawsuit, DJ Schanz, director of the campaign proposing the initiative, called on Drug Safe Utah to let the public debate the measure.

“We are beyond dismayed at the repeated attempts to undermine and stymie the democratic process and citizen participation by the Utah Medical Association and their allies,” Schanz said in a statement. “The time for parlor tricks and political grandstanding should be over.”

The initiative would allow people with conditions from cancer to chronic pain to buy and consume marijuana from privately run dispensaries supplied by private growers. It is similar to a bill that passed the Utah Senate in 2016 before it failed in the House.

After the initiative campaign formed and began to move forward, the Legislature this year approved a scaled-back version that allows people who are expected to die within six months to buy marijuana from a state-run dispensary. The Department Agriculture and Food is writing rules for that law.

The new lawsuit follows weeks of opponents seeking to prevent the idea from getting before voters. Ballot initiative campaigns must receive enough signatures in 26 of Utah’s 29 state Senate districts to qualify for the ballot.

Opponents hired canvassers to go door to door, persuading voters who’d signed the petition to change their minds and take steps to remove their names. They hoped to get enough signatures removed to stop the petition short of qualifying for the ballot.

In its filing, Drug Safe Utah effectively says that unless the court agrees to stop Cox from putting the question in the ballot, it has enough signatures.

“Because the defendant erroneously approved the initiative for signatures,” the lawsuit reads, “it will be placed on the November ballot unless enjoined.”