Gov. Cuomo’s just-announced tax cap hit an unexpected snag yesterday as a key backer cried “bait-and-switch” over an undisclosed poison pill and threatened to remove his support.

E. J. McMahon, the Manhattan Institute’s respected chief fiscal analyst, called Assembly Speaker Sheldon Silver’s continued insistence on a “sunset” expiration date for the historic property tax relief plan a “deal-breaker” .

“I will not support the bill if they put a sunset date in it because it will then become a temporary tax cap and that is not a good enough solution, not a real tax cap,” McMahon told The Post.

“A tax cap will work if it’s permanent, not temporary,” McMahon continued. “This feels like a bait-and-switch.”

McMahon initially offered unqualified praise for the 2-percent limit on annual property tax hikes Tuesday after it was unveiled by Silver and endorsed by the Cuomo. Support from the one-time aide to ex-Republican Gov. George Pataki provided a critical seal of approval to the Democrat-crafted plan.

But McMahon said he based his support on a Silver bill draft that explicitly stated the cap on suburban and upstate property taxes would exist as long as New York City’s decades-old rent regulations also continued.

Silver threw all that into question during a radio interview yesterday.

“When you see the bill actually, the actual final bill, the contemplation is it will have a specific date in it,” Silver told Albany’s Talk 1300-AM. “The date will correspond to the date that rent regulations expire.”

Pressed whether the property tax cap would be dependant on the existence of the “emergency” rent regulations or vice versa, Silver replied: “No. But they will expire simultaneously.”

A Cuomo administration source confirmed the final bill would include a specific expiration date.

“A bill with an expiration date is a bill that will be far too easy for one house to kill in the future, and that I should think would be regarded as a deal breaker,” McMahon said.

Such criticism could give the Republican-led Senate a reason to stall or kill the bill. Senate Majority Leader Dean Skelos (R-Nassau) specifically cited concern about the sunset provision in withholding his final sign-off Tuesday.

Cuomo himself struck a cautious tone about the deal while in Utica to push his legislative agenda.

“In Albany, nothing’s done until it’s done, but this would be an historic step forward,” Cuomo told a crowd of about 300. “I’m very excited about it and we’re keeping our fingers crossed.”

Read article here