Sen. John Fetterman may be allowed to dress like a slob in the halls of power — but it’s still a capital offense in New York City’s finest restaurants.

Intrepid Post reporter Jon Levine learned that hard truth this week when he crisscrossed the Big Apple’s culinary landmarks wearing Fetterman’s trademark hoodie, gym shorts and sneakers and tried to gain entry — only to face scorn and mockery from maître d’s with more common sense than Congress.

“He would not be permitted here,” sniffed a maître d at Daniel on the Upper East Side, where a seven-course tasting menu runs $275.

She admitted she didn’t know who Fetterman was.

“We have turned away guests for being improperly dressed regardless of their occupation,” she continued.

At famed Le Bernardin, a suited maître d named Julien served up an amuse bouche of stink-eye when The Post arrived.

“No athletic wear,” he said flatly, staring The Post down and denying even a nibble of chef Eric Ripert’s $480 dinner and wine pre-fixe menu.

The three-Michelin-starred dining room is reservation only but walk-ins are normally afforded the more casual lounge — but not if you’re dressed like you just came from Pilates class.

Le Bernardin’s wine director, Aldo Sohm, said jackets and pants were on loan to those with Fetterman’s fashion sense.

At the double-Michelin star Jean-Georges near Columbus Circle, no less than four sentinels outside its dining room vetoed The Post’s entry, ending the dream of feasting on the famed $368, 10-course tasting menu that includes caviar salad, king crab and smoked squab.

“Inside we don’t allow shorts,” said one, repeatedly insisting it would be “impossible” to get around the dress code, which also forbids jeans, sneakers and sweatshirts.

“It doesn’t matter if it’s Lady Gaga,” chimed in another.

A third was so stunned by the sartorial sacrilege, she couldn’t even finish her sentence.

“It doesn’t matter if it’s Lady Gaga,” chimed in another.

“I’ve never had anyone come in dressed like …”

The Post was allowed to use the bathroom.

Workers at The Grill — an ultra-lux chophouse occupying the legendary Four Seasons Restaurant space in midtown — wasted no time rejecting the faux Fetterman, holding the door tightly shut after they caught one glimpse.

“If you went and got a pair of jeans it would work,” offered a doorman named Don who boasted, “We treat the billionaires just like millionaires.”

It wasn’t all bad news for Fetterman.

The Post strode into Nobu and Gramercy Tavern without so much as a peep.

Masa, whose famed sushi bar omakase experience runs over $1,000 a person, was happy to receive us.