Mayor Eric Adams vetoed a package of City Council bills on Friday that reformed and expanded the Big Apple’s housing voucher program, claiming that lawmakers overstepped their legal authority.

Hizzoner’s decision sets up a showdown with lawmakers and comes just hours after Council Speaker Adrienne Adams said that any veto would simply be “theater” after the body passed the measures with enough votes to override it.

“Today, we helped New Yorkers once again by vetoing a package of bills that would take us backwards, by leading to longer shelter stays for the most vulnerable New Yorkers, while simultaneously creating a structure that could saddle taxpayers with billions of dollars in costs each year,” Adams said in a statement.

The brawl between the administration and Council erupted amid the contentious negotiations between the two sides of City Hall over Hizzoner’s proposed $106.7 billion spending plan, which must be completed before July 1.

The vetoed package would end a provision that requires people to stay in a shelter for 90 days before becoming eligible for a voucher, a provision that the mayor eventually embraced.

Adams eventually embraced and separately implemented the rule change through his executive powers, adopting the argument from lawmakers that it would help reduce crowding in New York’s overburdened shelter system.

The four bills would also allow New Yorkers facing eviction to apply for a housing voucher without first entering the shelter system, would bar landlords from deducting the cost of utility bills from a voucher and increase the income-level cutoffs to qualify for aid.

City Hall had estimated the legislation would cost as much as $17 billion over five years, a tally fiercely disputed by the authors of the legislation, who peg the figure at approximately $10 billion.

One of the top sponsors of the vetoed legislation, Councilwoman Diana Alaya (D-Manhattan/The Bronx), told The Post she was confident her colleagues would have the votes to override Adams’ attempt to block their bills.

“We’ve always felt confident that we had the votes to override the veto,” said the lawmaker, who chairs the committee that oversees the administration’s response to the homelessness crisis. “I see this more as a symbolic gesture of the mayor of his claims that these bills are not good.”

She added: “I’m not surprised, but I’m still disheartened.” 

Council sources say that city rules give lawmakers a month to formally override the veto.

It would be the first time lawmakers have done so since 2013, when lawmakers led by then-Council Speaker Christine Quinn overrode Mayor Michael Bloomberg’s veto of a police reforms package.

Quinn now heads WIN, one of the city’s largest non-profit operators of shelters for women and children, and was one of the loudest proponents of the voucher expansion.

“Make no mistake, vetoing these bills will prolong homelessness for New Yorkers and put an unnecessary strain on the City’s budget,” she said in a statement. Other lawmakers and advocates quickly joined the charge.

Other lawmakers and advocates quickly joined the charge.

Brooklyn firebrand Charles Barron (D-Brooklyn) told reporters at City Hall that it was a waste of a veto. “I think Adams is being stubborn,” adding that he thought the mayor was “on a delusional power trip,” according to The City.