Even as Mr. de Blasio resisted these cuts and others, he had to beat back questions that took city officials and onlookers alike by surprise. At least eight different lawmakers pressed him to explain why the city does not abide by a cap on property taxes that applies to other municipalities. Republicans have previously proposed forcing the city to impose the cap, but the issue also gained traction during the hearing with several city Democrats who want tax breaks for homeowners they represent.

As the mayor spoke, the Senate was passing a bill to impose the cap on the city, a move the Republican majority said would save city taxpayers $4.5 billion by 2019. The Democratic majority in the Assembly dismissed any possibility that it would follow suit.

“I believe that New York City, although larger, although having a unique set of circumstances, if we’re one state, then we’re one state, and we should be under the same guidelines to save our taxpayers dollars,” said Senator Kathleen A. Marchione, a Republican from Saratoga County.

The tax cap, passed in 2011, prevents local governments from increasing property tax rates by more than 2 percent each year.

Tax-cap question after tax-cap question, Mr. de Blasio responded the same way. He said the city’s financial situation was different from other municipalities’, as it funds services that others do not. He suggested that the city, as the prime driver of the state’s economy, needed resources to continue growing. And he warned of future fiscal tempests, saying the city should save its surplus — currently under threat from the governor’s proposals — for an especially rainy day.

“We will continue to build the New York City economy for the good of the whole state, with many benefits for the entire metropolitan area and the entire state,” the mayor said. “That’s my argument about why I think we should avoid a strategy that could limit that growth and our ability to handle the downturns when they do come.”

Mr. de Blasio also noted that the city is the only municipality in the state that receives no direct, unrestricted aid from Albany. The mayor’s aides later dismissed the property tax issue as a distraction, pointing out that the effective property tax rate on city homeowners was less than a third of the rate in the counties surrounding the city, and fiscal analysts, as well as other Democrats, chimed in with their own criticisms.