Top Republicans in the Minnesota Legislature have filed a lawsuit against Gov. Mark Dayton, a dramatic finale to the 2017 session that could set a legal precedent for state politicians for decades to come.

The lawsuit, which was filed in Ramsey County District Court Tuesday afternoon, argues the governor violated the state’s Constitution when he signed state budget bills but vetoed about $130 million in funding to operate the Minnesota House and Senate over the next two years. Republicans in control of the Legislature said that move violated the separation of powers clause in the Constitution, which says the executive, judicial and legislative branches are separate and one branch cannot interfere with the functioning of the other. 

“We need to protect the integrity of the institution of the House and Senate — of the legislative branch of government,” Republican House Speaker Kurt Daudt said Tuesday morning. “We will pursue a legal option to preserve that co-equal branch of government.” 

The lawsuit has been in the works since Dayton’s veto in May, but it was filed Tuesday after an unproductive last-minute negotiation session between Republicans and the governor’s staff to try to find a solution outside of court.

Dayton said he vetoed funding for the Legislature after Republicans put a provision in another bill that made funding for the entire 1,300-employee Department of Revenue contingent on his signing their $650 million tax cut bill. He called it a “reprehensible sneak attack” and wanted to compel Republicans to come back to the table to negotiate tobacco tax cuts, business property tax breaks, as well as new policies in other budget bills that affected immigrants and teachers. Republicans said Dayton was trying to walk back their agreements on the budget bills.

“They’re sticking with their position and I’m sticking with mine,” Dayton said. “Putting policy measures into budget bills is putting a gun to the head of the executive branch.” 

For the Legislature, time is running short. Without some solution, funding to pay salaries for hundreds of staffers and all 201 legislators will stop on July 1. The House has about $8 million in reserve funds that could keep them operating for about two months, Daudt said, but the Senate timeline is much shorter, with only about $4 million in reserves. As part of the lawsuit, Republicans are asking the courts for a temporary restraining order to fund the Legislature until there’s a resolution.

Complicating matters further, leaders said, are payments due on the new Senate office building, which costs the chamber about $8 million a year. Without bond payments to the building, they risk eviction and it could hurt the state’s credit rating. “We will prioritize our staff over the building,” Senate Majority Leader Paul Gazelka said.

Dayton said the layoffs do concern him, but he said that legislators can come back before July 1 in a special session and deal with the problem. He added that he signed the other budget bills to avoid a government shutdown, which happened during his first budget session, in 2011. That historic, 20-day shutdown left thousands of state employees out of a job for weeks. 

The governor and leaders said they would continue to try to find a solution outside of court, but the case is moving ahead anyway.

Most legal experts expect the lawsuit to be fast tracked up to the Minnesota Supreme Court, which has the option to not take the case. Last month, the New Mexico Supreme Court refused a complaint from the Legislature after Gov. Susana Martinez vetoed their funding, arguing there was time for them to work out a solution. In New Mexico, legislators had already scheduled a special session to deal with outstanding budget matters when the lawsuit was filed. 

But in arguing their position, Republicans have cited the 2011 court case that came out of the government shutdown, in which judges ruled that the Legislature is an essential branch of government and must be funded. Dayton has repeatedly argued that governors are given authority in the Constitution to line-item veto budget provisions. “I acted within my constitutional authority,” he said.

Budget battles have wound up in the courts before, but this year’s case is different. The result of any court battle could set legal precedent long into the future on whether one branch of the government can eliminate funding for the other.

“If we’re going to do this, I would rather settle it once and for all,” Gazelka said. “I don’t think any governor should be able to defund the House and the Senate, the judiciary branch. All of those are important, so it would be my preference that they settle it.”