The state Senate voted overwhelmingly Thursday to require that school districts offer free full-day kindergarten to all students by 2015.

SALEM — The state Senate voted overwhelmingly Thursday to require that school districts offer free full-day kindergarten to all students by 2015.

Lawmakers from both parties approved the bill without giving schools any additional money, saying the economy should improve over the next four years and the Legislature has plenty of time to figure out how to pay for it.

"This is about our kids, and this is about improving the system of education so our kids can have the best chance," said Sen. Jeff Kruse, R-Roseburg.

The 27-3 vote came despite objections from school officials, who said they fervently support full-day kindergarten but want the state to pay for the added cost of educating students for a full day.

Sen. Ted Ferrioli of John Day, the Republican leader, said the measure is a "feel-good bill" that gives lawmakers something to brag about but ignores the tough question of funding.

"This really is a bill that is the triumph of symbolism over substance," Ferrioli said.

Sens. Brian Boquist, R-Dallas, and Chip Shields, D-Portland, also voted against the bill, SB 248.

About one of every three kindergartners in Oregon is currently enrolled in full-day kindergarten — nearly 15,000 students in all, according to data from the Oregon Department of Education. Each kindergartner counts as half a student in state enrollment-based funding calculations.

The 108 districts that offer full-day kindergarten have to either absorb the additional cost or charge tuition to parents who want to enroll their children in the program — an arrangement that unfairly leaves out low-income families and poor districts.

Lawmakers cited studies showing that young pupils who spend more time in the classroom tend to be more successful later in their schooling. Spending more time in kindergarten will help pupils learn to read by third grade and keep up with their classmates, which are important benchmarks to prevent them from dropping out when they reach high school.

Sen. Mark Hass, D-Beaverton, said Oregon kindergartners spend only about 21/2; hours in school every day, so "kids barely have enough time to take off their coats before they have to put them back on and go home."

The Oregon School Boards Association and the Confederation of Oregon School Administrators, two lobby groups, say the bill would cost schools $100 million. The mandate comes at a time when schools are contemplating massive cuts in funding for the coming school year.

"SB 248 advances a goal we all support, but without additional funding it is a burden school districts cannot bear without carving out another area of a student's school experience," the organizations wrote in a letter to senators.

Gov. John Kitzhaber released a statement Thursday saying he supports the measure.

"Ensuring that Oregon students receive high quality education is a top priority," Kitzhaber said.