INDIANAPOLIS (AP) — Organizers expect a large turnout Saturday at a rally against Indiana's newest law that opponents say could sanction discrimination against gay people.

The law's supporters, however, say discrimination claims are overblown and insist it will keep the government from compelling people to provide services they find objectionable on religious grounds.

The rally will be held Saturday afternoon in Indianapolis. It comes at a time when local officials and business groups around the state hope to stem the fallout, though criticism over the law has spread across social media — with the hashtag #boycottindiana — and to the White House.

Republican Gov. Mike Pence signed a bill Thursday prohibiting state laws that "substantially burden" a person's ability to follow his or her religious beliefs. The definition of "person" includes religious institutions, businesses and associations. It will take effect in July.

Supporters of the law maintain courts haven't allowed discrimination that to happen under similar laws covering the federal government and in 19 other states. Pence has said opponents mischaracterized the measure and that it was solely a limit on government restricting people's religious liberties.

But some national gay-rights groups say lawmakers in Indiana and about a dozen other states that have proposed such bills this year are essentially granting a state-sanctioned waiver for discrimination as the nation's highest court prepares to mull the gay marriage question.

Indiana's move has been widely criticized by businesses and organizations around the country, and stickers touting "This business serves everyone" have been appearing on windows in many Indiana businesses. The Indianapolis-based NCAA has expressed concerns about the law, and has suggested it could move future events elsewhere; the Final Four will be held in the city next weekend.

Indianapolis Mayor Greg Ballard, a Republican who opposed the law, said he and other city officials would be talking to many businesses and convention planners to counter the uproar the law has caused.

"I'm more concerned about making sure that everyone knows they can come in here and feel welcome," Ballard said.

Groups such as the Indiana Chamber of Commerce have taken to social media with messages that the state is full of welcoming businesses. Democratic South Bend Mayor Pete Buttigieg touted on Twitter his city's civil rights ordinance's protections for gays and lesbians, while Republican Evansville Mayor Lloyd Winnecke wrote that the law "sends the wrong message about Indiana."

Indiana University law professor Daniel Conkle, who testified in favor of the bill in legislative committees and says he is a supporter of gay rights, believes the predictions of negative implications are unjustified. He also said he didn't know of any cases under states' laws or the federal statute, which dates to 1993, where a court had sided with a religious objector in a discrimination case.

"This 'license-to-discriminate' argument that seems to have this relentless repetition is just legally wrong," Conkle said Friday. "It is as if you just keep repeating something often enough it takes on a life of its own."

Indianapolis' tourism and convention business is estimated to have a $4.4 billion annual economic impact with some 75,000 jobs. Chris Gahl, a vice president of Visit Indy, said the tourism agency is pointing out to convention planners that some large cities — such as Chicago and New Orleans — are in states that have religious objections laws.

"We know that their ability to work is largely dependent on our ability to score convention business and draw in events and visitors," Gahl said.