PHOENIX (Reuters) - Arizona voters have narrowly approved a plan to pump $3.5 billion into education coffers over the next decade and put an end to a long-running legal battle, Republican Governor Doug Ducey said late on Thursday.

ICSS - Securing Sport 2015 - Harold Pratt House, New York - 3/11/15 Governor of Arizona, Doug Ducey, speaking at Day 1 of Securing Sport 2015 - the annual conference of the International Centre for Sports Security (ICSS) Photo Hilary Swift for ICSS Livepic

The measure, approved by state lawmakers and Ducey last year, provides for Arizona to tap its land trust fund and provide an additional $300 for each student, from kindergarten through 12th grade, in public and charter schools.

Arizona has historically ranked near the bottom of states in funding education.

The latest unofficial results from Tuesday’s special election showed the measure garnering 50.82 percent of votes cast throughout the southwestern U.S. state, and while some 30,000 votes remained to be counted, Ducey declared victory.

“This is a huge victory for public education in Arizona,” Ducey said in a statement. “After years of lawsuits and fighting, we are moving forward and funding our teachers, students and schools – instead of lawyers.”

Voter approval was required because the measure involved a change to the state’s constitution.

The narrow margin of the result proved that a sizeable number of voters disliked the plan, said Morgan Abraham, chairman of the “No” campaign.

“This tells me that voters want to fund education the right way, not through the trust fund, but with general funds,” Abraham said, adding that he was disappointed by the outcome of the vote.

Much of the controversy during the campaign centered on the funding, with critics saying Arizona was jeopardizing its future by taking too much money from its land trust fund.

About 60 percent of the new money will come from the trust fund, and the rest from the state’s general fund.

The governor’s office brokered the deal in a bid to end a 2010 lawsuit by a group of school districts and organizations that charged Arizona with failing to fund mandated inflation adjustments to schools during a recent recession.

The state’s highest court already had ruled in favor of the plaintiffs and the court case was being appealed by the state at the time of the deal.