SEATTLE — All nine of Washington state’s charter schools will remain open for the entire school year, despite a ruling from the Washington Supreme Court that found them unconstitutional, the head of the Washington State Charter Schools Association said Tuesday.

The 6-3 ruling late Friday afternoon said charter schools do not qualify as “common” schools under the Washington Constitution and cannot receive public funding intended for those traditional public schools.

The decision cast doubt on what would happen to the 1,200 students in charter schools, but Tom Franta, chief executive of the charter schools association, said Tuesday that all nine have committed to remaining open for the year, even if that means relying on private donations. The cost to operate the schools, which are in Spokane, Tacoma, Kent, Highline and Seattle, is estimated at $14 million a year.

“All of them have said unequivocally they will be open for the entire 2015-2016 school year,” Franta said. “We believe right now they are public schools and they’re entitled to public school funding. But if it so happens that public funding becomes unavailable, we are working with a large community of sponsors who want to make sure these schools stay open.”

Franta said the association believes the Supreme Court’s majority made several mistakes in its opinion and that the association’s lawyers would be acting within 20 days to ask the court to reconsider the ruling. Failing that, he said, the schools and their supporters were already lobbying Gov. Jay Inslee to call a special session of the Legislature to cure the constitutional problems the justices cited.

The state’s voters passed Initiative 1240 in 2012, making Washington the 42nd state to approve charter schools. The measure provided for the opening of as many as 40 charter schools within five years.

The first opened at the start of the past school year. This school year, eight more have opened, with classes beginning over the past few weeks.

The state teachers union, the League of Women Voters, El Centro de la Raza and the Washington Association of School Administrators were among the groups that challenged the law. They argued that the charter schools were siphoning money that would otherwise go to traditional public schools.