An angry Wake school board bucked county commissioners Tuesday and proceeded with a plan to convert 22 schools to a year-round calendar this summer.

The 5-2 vote appears to end the hopes of some of parents who had lobbied hard for a last-minute reprieve from the schedule. About 18,000 elementary and middle school students will be affected by the conversions.

The vote could set the stage for a protracted legal dispute between the school district and the commissioners. Also left unresolved is the status of several planned school renovations.

School board members were particularly angry that commissioners tried to attach conditions to the spending plan despite months of detailed discussions.

"It's pretty arrogant to try to control our policy issues with their purse strings," said school board chairwoman Patti Head.

The catalyst for the school board's anger was a decision by commissioners Monday involving an advance of $312 million from the $970 million in school bonds approved by voters in November. In the process, commissioners also rewrote the school district's spending plan, moving up new schools and delaying year-round conversions, new mobile classrooms and some renovations.

School leaders said they did not have time to come up with an alternative to year-round conversions, which will allow them to hold more students to keep up with growth.

"I don't see any other possibilities we have right now, given the time," said Superintendent Del Burns. "What we have to face is the 8,000 students who are coming and make sure we have seats for them."

The board quickly dismissed options such as half-day kindergarten and splitting students between day and afternoon sessions. That sparked the two dissents, with members Carol Parker and Horace Tart saying they needed to show they considered alternatives.

"We are the whipping boy for the community right now," Parker said. "We've heard that we're arrogant and aren't considering alternatives."

Opponent sees pattern

Dave Duncan, co-founder of the parent group Stop Mandatory Year-Round, said he was not surprised by the school board's decision. He recalled how the board signed a lease for a modular elementary school in 2005 on the DuBois Center in Wake Forest even after commissioners turned it down.

The board asked Burns to see whether there were ways to pay for the $7.3 million in year-round conversions and mobile classrooms without using bond money, but it left the far more expensive question of planned renovations for future debate.

That leaves projects in doubt at Lynn, Lacy, Poe, Root and Smith elementary schools as well as East Millbrook and Martin middle schools and Enloe High School. The renovations were part of the sales pitch for the bond referendum, but commissioners also objected to their scope and cost.

"It seems to me that certain people have made rash decisions not really knowing all the facts and the implications," Tart said of the commissioners' decision.

'We can't stop them'

It was not clear how commissioners will react to the board's decision.

Chairman Tony Gurley said reassignments and year-round schedules are clearly the legal responsibility of the school board. He said commissioners were simply trying to encourage the school board to reconsider.

"We can't stop them," he said.

Lawyers familiar with education issues said it's not clear which side has the upper hand.

School board attorney Ann Majestic said at first blush it seems commissioners are "usurping the school district" with their vote. Under state law, the school board has the power to set academic calendars, comply with class size requirements and make school assignments, while commissioners approve education finances.

The board asked her to research their legal options.

David Lawrence, a professor in the school of government at UNC-Chapel Hill, said state law also gives county commissioners some control over spending county money for school projects.

"It would seem to give them the authority," Lawrence said. "The county can allocate its money by project."

If the school board disagrees, Lawrence said, it can challenge the commissioners' decision through mediation and ultimately in court.

Feud flares anew

If that happened, it would mark an end to 18 months of detente between the two boards, which have frequently clashed but had mostly set aside their differences to get the bonds passed.

"It seemed that we had worked out an understanding on the bond issue and were singing from the same music," said Commissioner Betty Lou Ward, who opposed rewriting the spending plan.

(Staff writer Todd Silberman contributed to this report.)