(Reuters) - The maker of Tofurky meat substitute on Thursday urged a federal appeals court to strike down a Missouri law making it a crime to misrepresent a plant-based product as a meat product, one of several similar state laws the company is fighting around the country.

Anthony Rothert of the American Civil Liberties Union of Missouri argued for the Turtle Island Foods SPC, which does business as Tofurky Company, saying the law violated its right to free speech under the First Amendment.

Justin Smith of the Missouri Attorney General's office, arguing for the state, countered that Tofurky has nothing to fear from the law, which bans only statements that falsely represent a product as meat, and would not apply to products clearly labeled as plant-based.

Circuit Judges Steven Colloton and Jane Kelly and Senior Circuit Judge Michael Melloy gave no clear indication about how they might rule.

Missouri in 2018 passed a law that made "misrepresenting a product as meat that is not derived from harvested production livestock or poultry" a crime, punishable by up to one year in prison.

Tofurky sued the state that year in the Western District of Missouri, seeking a preliminary injunction blocking the law from taking effect. U.S. District Judge Fernando Gaitan denied the motion, agreeing with the state that because the law only bans false statements, Tofurky had not shown it would likely be harmed.

Tofurky won an injunction against a similar law in Arkansas, and recently filed a lawsuit against another such law in Louisiana.

Smith argued Thursday that the Arkansas law was different in a crucial respect: it banned "representing" a plant-based product as meat, rather than "misrepresenting," and so could be construed to cover the use of words like "sausage" or "burger" to describe plant-based products.

He said that Missouri's law would not ban Tofurky's marketing because it labels its products as "plant-based" and is "not untrue, misleading or deceptive."

"There's no evidence in the record that there is any threat of irreparable harm," he said.

Rothert, however, said that any of the state's independent county-level prosecutors could interpret the law differently. He said that the law created a "chilling effect" on his client's free speech.

"Reasonable people could decide to prosecute Tofurky, and therefore a preliminary injunction is appropriate," he said.

Rothert also said, as Tofurky has argued in its other legal challenges, that the use of meat-related words is not misleading.

"I don't anyone thinks there's butter in peanut butter," he said. "It tells you what texture to expect."

The case is Turtle Island Foods SPC et al v. Thompson, 8th U.S. Circuit Court of Appeals, No. 19-3154.

For Tofurky: Anthony Rothert of the American Civil Liberties Union of Missouri

For the state: Justin Smith of the Missouri Attorney General's office