With 50 new charter school slots to fill by next year, Mayor Bloomberg said the city is “hitting the ground running” after years of waiting for the statewide cap on the schools to be lifted.

After a litany of praise for the finalized state budget, which will raise the statewide cap to 200 from 100 and add millions of dollars to city education coffers this year, the mayor switched to the attack against charter school opponents who worked to delay the cap lift.

In response to a question about a new requirement that charter schools hire unionized teachers if enrollment reaches 250 within two years, he said: “It is a disgrace that when you have such demand that there’s anybody, at any level of government, who’s trying to limit parents’ options, particularly given the success of most charter schools.”

The mayor also promised to publicly condemn each individual lawmaker at the state and local level who had tried to limit charter schools, which are funded with public money but operate largely outside the education bureaucracy.

“For reasons nonpedagogical, people are trying to limit parents’ choices,” he said, “These are the same people who stand up repeatedly and say, ‘I’m for parents; I’m to help protect my constituents.’ … If they’re not standing up for parents, I’m just going to point it out to everybody.”

The increase in the cap comes as some charter school administrators are reporting a growing gap between a large number of applicants and a limited availability of seats this spring.

Department of Education officials later reacted with much less ire to questions about the union requirement.

“We don’t see it as a problem,” the director of new schools, Garth Harries, said. “It’s not the bill that we would have written, but it’s absolutely a bill that we can live with.”

Charter school groups were also relatively unfazed by the union provision, saying it was something they could work around.

The executive director of Harlem RBI, an organization that runs after-school programs in East Harlem, Richard Berlin, said his organization has been waiting to open a school for two years. His plans for the school, outlined in a 1,300-page application already submitted to the Department of Education, include a longer school day and year than at traditional public schools. The school will start small, avoiding the union requirement.

“It would have made it hard for us to run our school,” Mr. Berlin said.