Well, that was quick: two days after New York City’s new salt labeling rules went into effect — requiring chain restaurants to slap a salt shaker symbol on especially salty menu items — a restaurant group is suing the city, arguing that health regulators have gone too far.

The National Restaurant Association sued Thursday, claiming the city’s health officials overstepped legal bounds in enacting the first-of-its kind rule. That rule requires any menu item at a chain restaurant that exceeds the daily recommended limit of 2,300 milligrams of sodium with a salt shaker symbol, as part of the city’s effort to help residents make healthy choices.

It’s not like the lawsuit is a surprise: the group had vowed to fight back against the rule as it made its way from the idea phase to a requirement approved by the city’s health department.

“Ironically, this regulation will confuse and mislead consumers into potentially making less healthy food choices through the law’s spotty, inconsistent application and inaccurate scientific distortions,” says a copy of the lawsuit obtained by the Associated Press.

The association went back to a common criticism in the restaurant industry: what with federal regulators currently working on nationwide menu labeling rules, the city’s requirement just makes things more difficult for restaurateurs who will have to change their menus when those rules are final as well. The group also calls the salt warning “nonsensical” in applying to some food vendors and not others, and claims it violates restaurateurs’ free speech rights by making them put a warning on something it disputes as based on “scientifically controversial opinion.”

NYC’s Law Department says it’ll review the claim but is “confident that the Board of Health has the authority to enact this rule.”

On the side of the restaurant association is the Salt Institute, which has also come out against the warning labels along the rule’s path from inception to implementation.

“Regulations to discourage salt consumption are sending the wrong message,” said Lori Roman, president of the Salt Institute, which is supporting the restaurant association’s lawsuit.

While the new rule went into effect Dec. 1, NYC won’t be enforcing it until March. The warning labels will apply to about 10% of menu items of chains with at least 15 outlets nationwide, health officials say, with those chains doing about a third of the city’s restaurant business.

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