The Minnesota Supreme Court says Gov. Mark Dayton’s veto of the Legislature’s budget was constitutional.

The ruling Friday is counter to a lower-court ruling this summer that Dayton had acted unconstitutionally, but is not the last word in the case. The high court ordered the two sides to hire a mediator, by Tuesday, to resolve the dispute outside the courts.

The months-long legal battle arose this spring when Dayton line-item vetoed lawmakers’ $130 million operating budget. Dayton says he wanted to force lawmakers to rework costly tax breaks and other measures he signed into law, but the Legislature instead sued.

The state’s highest court was tilted firmly in Dayton’s favor. He had appointed four of the six justices presiding in the case.