Moviegoers settling in to see Batman v Superman at Columbus Boulevard's United Artists Riverview Plaza Stadium 17 theater over the weekend got an argument on the sugary-beverage tax before the trailers ran.

Theaters around the city are playing antitax commercials free of charge, as part of an effort to defeat Mayor Kenney's proposed three-cents-per-ounce tax.

The tax would be levied on distributors, but theater owners say moviegoers could expect to see the increase tacked onto the cost of already-pricey fountain drinks. If so, they say, a 24-ounce soda might rise 72 cents in price.

On Monday, Gina DiSanto, president of the National Association of Theater Owners of Pennsylvania, said cinemas would voluntarily air the ads, created by the No Philly Grocery Tax coalition and paid for by the American Beverage Association. So far, 10 theaters around the city have agreed to show the ads.

The ABA has already spent $1.5 million to run ads on radio and TV.

"We know that thousands of people from all corners of the city would have to pay more to see their favorite films because of this tax," DiSanto said. "This tax will hit moviegoers from Old City art houses to North Philadelphia megaplexes, and will prevent families from spending quality time together doing something they love."

Print ads are also popping up in grocery stores around the city. At the Port Richmond Thriftway on Aramingo Avenue, a sign on a cart filled with sugary drinks this weekend read, "The taxes on products in this cart alone would add $34.10 to your grocery bill."

Advocates say the tax is the fairest way to fund universal pre-K and community schools, and help pay for a bond to invest in parks and libraries.

"The soda industry makes billions of dollars in profits every year, much of it on the backs of the very people it now claims to be defending," said Kevin Feeley, spokesman for the pro-tax coalition, Philadelphians for a Fair Future.

"What's more, the industry has the choice to pass on the tax to consumers, or it can choose to redirect a small portion of its annual profits toward the tax. Either way, the sugary-drinks tax is the fairest way to pay for investments aimed at the city's toughest challenges: fighting poverty, improving public schools, and helping our struggling neighborhoods."

Feeley said theaters could afford to absorb the tax, given the markup on concessions. In 2014, Regal Entertainment Group, which includes United Artists theaters, and AMC Theatres, which operates the multiplex at Philadelphia Mills, got nearly 30 percent of their revenue from concessions, according to a Business Insider study.

On average, the two chains saw an 80 percent profit margin on sodas and snacks.

Movie theaters use concessions to make up for declining ticket sales, the study said, and to prevent ticket prices from getting even higher.; 215-854-5506; @jterruso

Staff writer Allison Steele contributed to this article.