AUSTIN, Texas A state judge overturned Texas' school finance system for the second time in 18 months on Thursday, ruling that the Legislature's funding boost last year failed to fix a system that is unfair and inadequate for the state's 5 million public school students.

State District Judge John Dietz of Austin decided in favor of the more than 600 school districts who sued the state. They argued the Legislature has consistently underfunded schools while imposing new and expensive academic requirements for students.

In his ruling, the judge also pointed to inequities in the system that leave lower-wealth school districts with far less money to spend on their pupils than their wealthier counterparts across the state.

"The court finds that the Legislature has failed to meet its constitutional duty to suitably provide for Texas public schools because the school finance system is structured, operated and funded so that it cannot provide a constitutionally adequate education for all Texas schoolchildren," Dietz wrote in his 21-page final judgment in the case.

He ordered funding to stop until the problems are corrected, though he put the ruling on hold until July 1, so schools won't be immediately affected. The state plans to appeal, probably straight to the Texas Supreme Court, which last ruled on school finance in 2005. That order forced the state to revamp its method of funding education so that it was less reliant on local property taxes.

"The state will appeal and will defend this (school finance) law, just as it defends all laws enacted by the Legislature when they are challenged in court," a spokesman for Texas Attorney General Greg Abbott said in a written statement.

If the Supreme Court affirms Dietz's new ruling, it would force the Legislature back to the drawing board. That would probably not occur until after the upcoming legislative session in January.

Abbott, the GOP nominee for governor, has sparred with his Democratic opponent, Wendy Davis, over the attorney general's defense of the school finance system in the case.

"This ruling underscores the crucial need to invest in education and reminds us of just how much our schools, teachers and students have had to sacrifice over the past three years just to get by," Davis said Thursday.

Plaintiff school districts praised the judge's ruling, while legislative leaders cautioned that Dietz won't have the final word on whether the funding system is constitutional. That rests with the Supreme Court.

Dietz also said lawmakers erred by sharply limiting the taxing ability of school districts, which amounts to an illegal statewide property tax. Texas annually spends nearly $60 billion a year on its schools, which includes billions in federal funding and local property tax revenue.

The judge originally found the funding system unconstitutional in February 2013, after a 12-week trial pitting the state against school districts including dozens from North Texas. But he withheld his final decision in the case after legislative leaders indicated they would address the issues raised by Dietz during their 2013 session.

Lawmakers did increase school funding by $3.4 billion in the current biennium. However, that did not make up for the $5.4 billion that was cut in 2011 to offset a severe shortfall in state revenue. Lawmakers also dropped 10 of the 15 high school tests that were slated to be required for graduation.

Dietz held additional hearings this year to decide whether the changes would temper his earlier decision.

They didn't.

Senate Education Committee Chairman Dan Patrick, the GOP nominee for lieutenant governor, insisted that lawmakers restored most of the funding cuts last year.

"We have spent vast amounts of money towards education and we're still struggling to see significant improvement," said Patrick, a Republican. "Spending continues to rise steadily while the number of failing schools increases."

Patrick also pointed out that "today's decision is the sole decision of one judge in Travis County. The final say will come from the Supreme Court."

His Democratic opponent, Sen. Leticia Van de Putte, said Patrick was partly responsible for the problem by resisting more education spending in last year's legislative session.