The city’s “Taxi Kingpin’’ is having trouble hacking it as he battles mounds of debt — thanks to Uber.

Gene Friedman, who owns more than 900 city cab medallions, has been hit so hard by the car-hailing app that he can’t meet his bills — and Citibank is now foreclosing on at least 90 of his medallions to recoup what he owes, court records and sources say.

“Gene Friedman’s business model requires him to lease out hundreds of cars every day, and because he can’t find drivers because of Uber, [it] means he’s not making money,” an industry source told The Post.

“All of these [medallion owners] borrow as much as they can against medallions, and they get cash-crunched when, all of a sudden, you get competition in the market.”

The value of the medallions plunged from $1.05 million in June 2013 to $800,000 this past January as Uber has lured drivers away.

“People used to have a religious faith that yellow-cab-medallion prices would go up forever,” a source said. “People’s faith has been rocked. Uber plays a big part in that.”

Citibank is now hauling Friedman to court March 24 to recoup the $31.5 million he owes in loans, court records show.

The business accounts that Friedman used to repay his loans had no funds — and even negative balances — as of early December, the papers say.

Friedman — who buys his medallions through companies with such names as Vodka, Bourbon and Bombshell — made partial payments but failed to pay off the debt in full, the documents say.

His spokesman, Ronn Torossian, said that Citibank’s suit came only because Friedman was two days late on a payment and that the rest of his debt was wrongly accelerated.

Torossian even hailed Uber, saying it “has done great things for the entire taxi industry.’’

Friedman’s lawyer, Brett Berman, claims Citibank simply wants out of the taxi business.

“This story is about a bank choosing to bail when industries change and not about financial stability,” he said.

A Citibank rep said the suit was “an absolute last resort” after other attempts to gain payment failed.

Friedman has faced legal action before. The state attorney general fined him $1.2 million in 2013 for overcharging cab drivers to lease his cabs.

But Friedman is still living large, with Page Six reporting that he threw a lavish bash this past July 4 in the South of France.