A high-stakes legal battle between Gov. Mark Dayton and the state Legislature is now in the hands of the state's top court, with six justices weighing a decision that both sides say would leave the other with an unprecedented amount of power over state government.

The Minnesota Supreme Court heard arguments Monday in the lawsuit filed by Republican legislative leaders after the DFL governor vetoed state funding earlier this year for the state House and Senate. A lower-court judge earlier ruled Dayton's maneuver was unconstitutional, which the governor appealed.

With Minnesota government's separation of powers in the balance, the 90-minute hearing in the high court's historic State Capitol chambers was lively. As Dayton himself and several top legislative leaders looked on, the justices peppered attorneys for both sides with questions — speaking over the attorneys and at times, each other.

"Can we just get to it?" Chief Justice Lorie Skjerven Gildea asked early on of Dayton's attorney Sam Hanson, a retired state Supreme Court Justice.

Hanson was arguing that Dayton did not functionally erase the House and Senate from existence, since legislative leaders are able to ask the court for relief until the governor and GOP lawmakers resolve the dispute that precipitated Dayton's veto.

Gildea sounded skeptical: "If it's constitutional for the governor to take money away from the Legislature, why is it constitutional for the judiciary to give the money back?" she asked.

Gildea and other justices wondered aloud about the precedent set if it's determined a governor could strike out funding for another branch of government.

Might a future governor take an even more aggressive stance against the Legislature, they wondered, or try to rein in the judicial branch by cutting off its budget?

Hanson argued that such speculation went beyond the bounds of the case.

He said Dayton was left with few choices after a budget-setting process last spring that took an unexpected twist.

Republican lawmakers inserted a provision in a $650 million tax-cut package that would defund the state's Revenue Department if Dayton didn't sign the bill.

Instead of vetoing that bill, Dayton stripped legislative funding in an attempt to get GOP leaders back to the negotiating table on a handful of issues: a collection of new tax cuts, teacher licensing standards, and driver's licenses for undocumented immigrants.

Hanson said the governor's move was meant to cause the least amount of harm to the state amid a challenging political situation.

"It was the least destructive solution," he said.

The Legislature's attorney, former federal prosecutor Doug Kelley, acknowledged that a governor's power to veto is enshrined in the state Constitution. But that doesn't mean unlimited power to clamp down on the power of another branch of government, Kelley said, arguing that because the Legislature had already adjourned for the session when Dayton issued his veto, lawmakers could not wield their own constitutional right to try to override the veto.

"The way [Dayton] has done it is that he has rendered one branch inoperative and unable to defend itself," Kelley said.

Some justices seemed leery. Justice Natalie Hudson took issue with Kelley's insistence that the governor's veto amounted to the legislative branch being "abolished."

"Aren't you engaging in a little bit of hyperbole?" she asked. "The Legislature is not abolished."

Kelley told Hudson he was quoting from the ruling of the lower-court judge, Ramsey County Chief Judge John H. Guthmann, who declared Dayton's veto null and void and said it amounted to "effectively eliminating a coequal branch of government."

"Well, we're here now," Hudson replied.

Four of the six justices now considering the arguments were appointed by Dayton, while two others — including Gildea — were appointed by the governor's predecessor, Republican Gov. Tim Pawlenty.

The seventh member of the court, Justice David Stras, recused himself from the case. Stras did not specify why he did not participate; Minnesota Supreme Court justices are not required to provide a reason for recusal.

After the hearing, Dayton appeared before reporters but answered only one question.

He asserted, again, that his action was within his rights.

"This case comes down, clear and simple, to the language of the Constitution," he said, "which gives me line-item veto authority."

Senate Majority Leader Paul Gazelka, R-Nisswa, and House Majority Leader Joyce Peppin, R-Rogers, spoke on behalf of the Legislature.

Both said Dayton overstepped his bounds.

"If [the court] rules in the governor's favor he has more power than ever before," Gazelka said.

It's not clear when the Supreme Court will rule. Gildea said only that the court will issue a decision on the matter "in due course."