A last-minute attempt to force schools to release more funding information could complicate a final deal on mayoral control of New York City schools.

As lawmakers left the Capitol Thursday night, it appeared they were zeroing in on a plan to extend mayoral control for one year. But Friday morning, State Commissioner MaryEllen Elia said she is fighting a surprise provision that would require the disclosure of individual school budget information, which she said lawmakers added around 11:30 p.m. Thursday.

“I think it’s difficult, adding something at the very end of the session without any consultation to the state ed. department and school districts,” Elia said.

That measure could be one of the final sticking points as lawmakers try to wrap up the session and go home — already a day after their self-imposed deadline. On Friday afternoon, lawmakers seemed less sure that a final deal was in sight. If lawmakers do not reach a deal by the end of the day, they might have to return next week.

“Things come together and fall apart a lot here,” said Assemblywoman Cathy Nolan, chair of education committee. “We have a ways to go yet.”

Senate Majority Leader John Flanagan defended the school funding measure as a way to force New York City to be more transparent.

“Let’s be very, very clear,” he said. “The City of New York is unique and special. The rest of the State publicly votes on their school budgets. There is a lot more transparency at the local level.”

But city officials said the measure would make the budget process untenable. School websites already list detailed budget information, they said. But this mandate would force principals to create budgets months before they have a sense of what they need for the school year, city officials said.