The earliest the bill could be voted into law is at the Council’s next full meeting, on Feb. 3. But the skepticism voiced at the hearing — and the lack of answers to key questions about the plan — suggested that it might take longer.

“I felt insulted,” said Councilman Jimmy Van Bramer, a Democrat from Queens. “They failed at every single turn today. As a result, I’m less likely to support the legislation.”

Still, the proposed bill — supported by the Council speaker, Melissa Mark-Viverito, a Democrat, and negotiated between the de Blasio administration and the local Teamsters union, which represents the carriage drivers — appeared likely to pass in some form. Officials with the union, which supports many council members, said discussions began in June and were continuing.

The union’s secretary-treasurer, Demos Demopoulos, said after his testimony that elements of the bill, like the number of horses, were still being discussed. “All those things we’re trying to tweak to make it more possible for the industry to operate,” he said.

When the particulars of the bill became public earlier this week, new opponents emerged. Parks advocates questioned the use of parkland and the expenditure of tax money for a private stable. And because the city proposed in the bill to ban pedicabs, a competitor to the horse carriages, from Central Park below 85th Street, pedicab operators protested at City Hall on Tuesday, and dozens more gathered at the hearing on Friday.