New York Gov. Kathy Hochul made an “unforced error” in picking moderate Hector LaSalle to be the state’s top judge when key backers of her reelection bid had expressed distaste for the choice, one of her predecessors charged Sunday.

“It’s sort of an unforced error because a number of parties had complained about this nomination, even before she made the selection,” former Gov. David Paterson said during an interview on WABC Radio’s “Cats Roundtable.”

“The governor is putting in the highest court in New York … someone who a lot of individuals who helped her thought would not stand for even what the governor stands for,” the fellow Democrat said. “It’s really kind of amazing that this whole thing happened.”

Hochul’s pick to head the state’s highest court upset unions and progressive groups who boosted her campaign against Lee Zeldin in what wound up being the closest New York governor’s race in decades, Paterson told host John Catsimatidis.

“The unions, the Working Families Party and other progressive forces really came together at the end to help the governor pull this out,” he said.

“I think they did not take very kindly to her first major action after this to take a judge whose record apparently from their point of view on labor issues is not acceptable, and who is thought to be not really in favor of the rights that women have in New York right now.”

Paterson had previously urged lawmakers in Albany to at least give LaSalle a hearing to explain his positions and his qualifications for the role.

“This is why we have a process. This is why we have hearings,” he told The Post last week.

Enough Democratic senators have expressed opposition to LaSalle’s nomination that Hochul will need Republican votes if she wants to jam the pick through.

Paterson, a former top state senator in Albany and lieutenant governor, became governor in 2008 after the resignation of Eliot Spitzer and served through 2010.