Mayor de Blasio is squeezing the city’s grocery and convenience-store chains by requiring them to post calories counts nearly a year ahead of a federal deadline, a new lawsuit charges.

“New York’s regulation will effectively govern calorie count obligations and displays nationally, and in a manner that the Food and Drug Administration considered to be so problematic that more time was warranted to make revisions,” according to a Manhattan federal suit filed by food-industry groups.

The National Restaurant Association and The National Association of Convenience Stores — which represent thousands of area chains such as Fairway Market and 7 Eleven — filed suit Friday to block the city from fining businesses that don’t comply with the regulations between $200 to $600 starting Aug. 21.

Under the FDA rule, businesses with 15 or more locations nationwide must display nutritional information including the federally recommended daily caloric intake of 2,000 calories by May 2018.

This includes restaurant chains, but the city has already been requiring those in the Apple to post such information on their menus since 2008.

The groups say the displays are particularly onerous on chains that offer custom items such as build-your-own salads and hot food bars, claiming that it costs up to $1,000 per item to craft the required calorie information and displays.

“The FDA staff could not provide clarification on basic questions, such as…how to provide calorie counts for fried chicken, given that chickens (and their various parts) come in different sizes,” the suit says.

The FDA delayed its deadline until May 2018 in response to industry concerns.

“Members should not be forced to alter their business models, or be marked as lawbreakers, because of New York City’s ill-considered decision to jump ahead of the national regulatory regime,” the suit says.

A spokesman for the City’s Department of Health said the mayor has no plans of backing down.

“We are confident that our updated calorie labeling rules announced this past May will withstand scrutiny. It’s just good, commonsense policy that benefits all New Yorkers,” the spokesman said.

Courts have already declared the menu requirements legal, the industry groups are just suing over New York’s fast-tracked implementation.