A national animal rights group will ask millions of its supporters to boycott vacationing in Iowa to protest the state's new "ag gag" law.

"People who care about animal rights, who don't want abusers protected, won't be visiting Iowa," said David Matulewicz-Crowley, legal advocacy counsel for Mercy For Animals.

Animal welfare groups say the law prevents exposure of abuses, such as slamming piglets into concrete floors and confining animals in small cages.

"It's one thing the people outside of Iowa have a say about," said Matulewicz-Crowley, whose group plans to launch a large social media campaign against Iowa travel.

Gov. Kim Reynolds signed a new "ag gag" law Thursday that makes it a crime for journalists and advocacy groups to go undercover at meatpacking plants, livestock facilities and other ag operations to investigate working conditions, animal welfare, food safety and other concerns.

Lawmakers said the bill is needed to help protect pig, cattle and other livestock operations from biosecurity threats.

It had widespread agricultural support, ranging from the Iowa Corn Growers Association and Iowa Farm Bureau Federation to the Iowa Honey Producers Association.

More:Iowa House and Senate approve new ‘ag gag’ bill despite concern over potential lawsuit

“Laws like this help further the security and safety of our farmers,” Reynolds said at Thursday's signing.

Matulewicz-Crowley said Mercy For Animals' boycott effort is similar to cities and states that banned government-sponsored travel to North Carolina in 2016, after the governor signed a bill restricting the bathrooms transgender people could use. The law was repealed and replaced in 2017.

While Iowa isn't a summer travel hotspot, the industry says vacationers will spend $8.5 billion this year. For example, Okoboji area visitors spend about $1 million a day over June, July and August.

Matulewicz-Crowley said he thinks the campaign could have an economic impact if it influences the travel plans of just some of "the millions of people who care about animals welfare."

Iowa lawmakers say the new law has been more narrowly crafted to avoid constitutional challenges that befell an existing law.

A federal court judge ruled in January the state's 2012 ag-gag law was unconstitutional, violating the First Amendment's free-speech protections.

Iowa Attorney General Tom Miller is appealing the federal court ruling. His office said Thursday it will "continue to examine how the new law will affect the appeal and how we should proceed."

The new law is similar to part of an Idaho ag-gag law that survived a constitutional challenge.

More:Iowa 'ag gag' law ruled unconstitutional, struck down by federal judge

The U.S. Court of Appeals for the Ninth Circuit said two provisions of the Idaho law — using misrepresentation to obtain records and employment with the goal of causing harm — should be allowed to stand.

But Iowa is within the Eighth Circuit Court of U.S. Appeals, and a federal court judge could read the state law differently, said Neil Hamilton, a Drake University agricultural law professor.

"People are pointing to language on the Idaho law, saying it wasn’t as problematic," he said, but that may not "carry water in Iowa."

"It's fair to say that federal courts have been hostile to ag gags and found them to be a restraint on free speech," Hamilton said.

The Animal Legal Defense Fund, one of the groups that successfully challenged Iowa's 2012 law, said it's likely to challenge the new law, which opponents are calling "ag gag 2.0."

That means Iowa could find itself in two courts defending the state's efforts to protect its livestock industry.

"I believe it's still unconstitutional. Its intent is to silence critics of industrial animal agriculture," said Matthew Liebman, director of litigation at the Animal Legal Defense Fund, one of the groups that successfully challenged Iowa's 2012 law.

The new law is so "broadly worded that it would sweep in all types of protected First Amendment activities," Liebman said.

"Ag gag 2.0 once again tries to give special protection to agriculture over all other industries in our state, and over the free speech rights of those who would voice opposition to them," said Mark Stringer, ACLU of Iowa's executive director.

"It would have a chilling effect on exposing problematic worker conditions, health and safety violations, and animal cruelty," said Stringer, whose group was among those that successfully challenged the 2012 law.

Matulewicz-Crowley, Mercy For Animals' legal counsel, said Iowa taxpayers should consider if it's worth the expense to defend another ag-gag law.

The attorneys challenging Iowa's 2012 law are asking to be paid $200,000 to cover their costs. The attorney general's office says it's fighting the request.

Other states losing ag-gag law battles have been forced to pay attorney fees up to $350,000, Matulewicz-Crowley said.

Iowa has "been spending taxpayer money for years now just to violate the First Amendment," he said.

The attorney general's office said it paid $500 to appeal the 2012 federal court ruling, but otherwise has had no cost outside normal staff time.