Raleigh, N.C. — A parents group on Tuesday filed a class-action lawsuit against the Wake County Board of Education seeking an injunction to stop the conversion of 19 elementary and three middle schools to a mandatory year-round schedule.

Leaders with the group, WakeCARES, want a judge to hear the complaint within the next 10 days, because the plan is expected to take effect beginning the 2007-2008 school year.

At a news conference Tuesday afternoon, leaders said they felt they had no choice but to sue the board, saying it did not listen to their concerns about the conversion plan.

For months, groups have argued, for example, that such a schedule would complicate lives of families who have children on different school calendars and potentially split families.

School board members would not comment on the lawsuit Tuesday afternoon, saying they have not yet been briefed about the complaint.

School system leaders have said that without the conversion of those schools, they will be at least 4,000 seats short for the start of next school year.

Year-round schools are necessary, they argue, to help the system manage its booming student population, because they accommodate about 25 percent more students. While three-quarters of students are in class, one quarter is always on break.

Tuesday's lawsuit is the latest move in the battle over mandatory year-round schools.

In January, days before the school board was to approve a massive reassignment plan -- which is based on the 22 school conversions, the Wake County Board of Commissioners voted to withhold $3.4 million in funding to transition the schools.

The school system, however, moved forward with the reassignment plan, reallocated funding from its budget.

In the last three years, enrollment in the Wake County schools has grown by more than 16,000 students. This year, about 6,400 new students enrolled.

By 2020, the county is expected to grow to 1.1 million people, meaning there would be an estimated 180,000 children in Wake County schools.