A pro-landlord member of the city’s Rent Guidelines Board resigned in protest Thursday just hours before an anticipated vote to approve a rent freeze — arguing the panel was stacked to make Mayor Zohran Mamdani’s campaign pledge a reality.

Christina Smyth — a representative for property owners appointed by former Mayor Eric Adams — released a scathing resignation letter, claiming the 9-member board “stopped being a fact-finding body” and was rebuilt “to deliver a rent freeze” no matter what.

“Everything else has been theater,” Smyth wrote, arguing her now-former colleagues were ignoring evidence as they determined the fate of 1 million rent-stabilized homes across the five boroughs.

“The hearings, the reports, the public comment, the data. None of it was ever going to change the result,” she wrote.

The incredible public rebuke came as the RGB was widely expected to pass a two-year rent freeze for stabilized units — delivering one of Mamdani’s key campaign promises that helped fuel the far-left pol’s astronomical rise to power.

In a Thursday morning social media post, Mamdani’s comrades in the city’s Democratic Socialists of America chapter were already cheering the anticipated rent freeze.

“Just days after our candidates sweep their elections, we’re going to deliver a rent freeze for millions of New Yorkers!” the group wrote an X.

But Smyth, a real estate attorney and law firm owner, accused the board of crossing a “legal line” by “knowingly disregarding its own evidence” showing landlords face spiking operating costs, during the lengthy process to decide whether to adjust rents.

“I asked the questions a board member is supposed to ask. I asked the staff to explain their methodology. I asked how the figures in the operating cost reports were reached. I asked why data showing rising costs and falling net income was not reflected in the board’s direction to its members,” she wrote.

“Those questions went unanswered. They were too inconvenient to be answered.”

RGB Chair Chantella Mitchell said she was caught off guard by Smyth’s abrupt departure as she denied her allegations.

“I want to take this opportunity to affirm the independence with which this year’s board members have served, along with the rigor and integrity demonstrated by the RGB staff in preparing and presenting data,” Mitchell said in a statement. “I thank them all, including Christina, for their service.”

Mamdani, asked about Smyth’s letter, also claimed — as he has repeatedly — that the RBG is independent.

“This Rent Guidelines Board is an independent board that has been conducting a process over the last many months,” he told News 12, “that it includes both fact finding as well as testimonies, and I look forward to the outcome and the decision they will make.

“It’s an independent board,” he repeated. “We trust them to make the decision they will make.”

Smyth, one of two landlord reps on the board, was among three Adams appointees on the panel. Mamdani appointed the other six members after taking office this year.

Her resignation likely won’t affect the expected vote, as only five members are required to be present, according to the board’s rules.

A rent freeze was last passed in 2020, for one year, under then-Mayor Bill de Blasio. But the anticipated incoming two-year freeze — which would cover both one-year and two-year leases for roughly 2 ½ million tenants — would reportedly be the first in the board’s history.

Smyth claimed the RGB’s determination was preordained on the campaign trail last year, as she accused members of turning a blind eye to data.

Research indicates that rent-stabilized buildings’ costs are rising more rapidly than inflation, including an increase in insurance expenses and property taxes, as well as fuel, water and labor while net operating incomes drop, Smyth wrote.

“Please understand me when I tell you that a freeze does not help the people it claims to protect,” Smyth insisted. “It does not lower the cost of running a building. It does not pay for a boiler or a roof or an elevator … When these buildings fail, it is not the people who cast these votes who pay the price.”

The makeup of the board includes two advocates for property owners, two for tenant reps and another five public members.

Tenants have argued keeping their rent flat would help them scrape by in a city where housing costs are sky high, but landlords have insisted they can’t properly operate the properties without an acceptable increase in monthly dues.  

Property owners have long been skeptical of the process leading up to this year’s vote, including questioning if City Hall’s new Office of Mass Engagement was lobbying for a rent freeze by spreading the word about RGB hearings.

City officials have claimed the initiative has sought input from both renters and landlords, and would not advocate for a side.

But landlord advocates feared Smyth’s letter indicated the board was anything but apolitical.

“She didn’t just quit, she pulled the fire alarm on her way out the door,” said Massimo D’Angelo, Real Estate attorney and partner at BlankRome. 

“For Smyth, this was never an independent dialogue between tenants and owners; it was a pre-written political script, and she refused to read her lines,” he told The Post.

D’Angelo said he believed legal action could ensue if a rent freeze was approved, stressing the RGB was “supposed to be bipartisan.”

New York Apartments Association head Kenny Burgos said he understood Smyth’s frustration.

“This process has always been overly politicized, but when the mayor made freezing the rent his signature campaign promise before any data was presented or testimony was given, he crossed a line and destroyed the RGB’s credibility,” he said.

Ann Korchak, president of the landlord-interest group Small Property Owners of New York, called the stated reasons for Smyth’s resignation “disturbing.” 

“If the vote is already predetermined by the majority Mamdani-appointed RGB, then this independent board would be acting illegally by injecting political influence into its objective decision on rent adjustments,” she told The Post in a statement.