A screenshot from the website of Future Leaders Institute Charter School shows that the school had planned to hold classes tomorrow even though Department of Education schools are closed. It no longer has permission to remain open, following two back-to-back policy changes by the city.

Reversing a decision made late last week, the Department of Education will provide school safety agents and other supports to dozens of charter schools that want to hold class on Tuesday.

But the reversal came too late for some schools that had already canceled classes.

On Friday, Chancellor Dennis Walcott decreed that no school housed in public space could remain open on Election Day because school safety agents were needed to fill in for other city workers pulled away to help with Hurricane Sandy relief.

“For all schools in DOE space, regardless if you have applied/have a permit, no students may be in the building and no classes may be held on Election Day,” Sonia Park, head of the department’s Charter Schools Office, told school leaders on Friday afternoon. “Because of the storm, significant resources across the City will continued to be deployed for recovery efforts and therefore can not be available for schools in DOE buildings.”

The decision brought charter schools housed in district buildings into line with the rest of the city’s schools, which were already scheduled to have the day off so that 700 schools could serve as polling sites.

But it also snatched away a key element of the privately managed schools’ autonomy: the right to set their own calendars. Dozens of charter schools were planning to hold classes to avoid a midweek interruption — particularly after Sandy caused them to miss five days of classes.

(Some city charter schools housed in private space had not planned to have classes on Election Day but chose to use it as a storm makeup day.)

Some charter school leaders pushed back against the decision, asking the department to reconsider, department officials said.

This afternoon, Miriam Sondheimer, who works in the department’s Office of Portfolio Planning, told charter school leaders that the department had reversed itself again.

“The determination has been made that charter schools can open tomorrow for students,” Sondheimer wrote in an email, which GothamSchools obtained. “We have confirmation that a safety agent will be in at the buildings in the attached list. There will be no transportation services, but there will be food services available.”

The list contained the names of 50 schools with permission to remain open on Tuesday. But Sondheimer also exhorted school leaders to let the department know by 3 p.m. if they had decided to cancel classes ”so that we can appropriately deploy our limited resources.”

By the end of the day, the number of charter schools that will remain open in public space on Tuesday had fallen by nearly half, to 32. Among the schools that will be open for business are all 14 schools in the Success Academy Charter Schools network, the six schools in the Achievement First network, and the three schools operated by Democracy Prep, which has a day of activities planned to tie in with the election.

A handful of independent charter schools housed in public space have opted to open on Tuesday, as well. One school that stayed on the list was Manhattan Charter School, which operates out of a Lower East Side building that lost power after Sandy for nearly a week. On its website, the school has posted its academic calendar: “Election Day – School is OPEN.”

Of the schools that fell off the list by relinquishing their right to remain open, fully half are members of the Uncommon Schools network.

“We were planning to be open, but DOE told us last week that we couldn’t be,” said Barbara Martinez, a network spokeswoman. “At this point, it’s too late to change the plan.”

The rest of the schools are independent charter schools scattered across the city. Dirk Tillotson, executive director of Fahari Academy Charter School, said the school simply couldn’t muster the resources to bring students back after telling them to stay home.

“We put in a lot of staff time and energy to translate messages, send out text messages, put out phone calls, and follow up when we were unable to get through,” Tillotson said. “It took a lot of energy to make that call and be sure that nobody would show up on Tuesday.”

He added, “At the same time we had a very interesting program scheduled for that day, so it was disappointing. But at the same time, I’m sure there’s a lot of competing demands for the building and they’re doing their best.”