The state’s largest employee union on Friday notched a win in its war with Gov. Bruce Rauner after an appellate court put on hold a declared impasse in negotiations to reach a new contract.

The ruling effectively stops Gov. Rauner from being able to implement the state’s final contract offer — and it puts the brakes on the potential for state workers to strike. An appellate court must now rule on whether an impasse exists, and that could take months.

The 4th District Appellate Court granted The American Federation of State, County and Municipal Employees Council 31’s request to put on hold the impasse that was declared by the state’s labor board.

Roberta Lynch, AFSCME Council 31’s executive director, said in a statement she’s now urging Rauner to return to bargaining in “good faith” to reach an agreement.

“Today’s decision is in the best interest of all the people of Illinois, both public service workers and the millions of citizens who rely on their important work,” she said.

The Rauner administration in a statement said it’s “disappointed” with the ruling, and argued that its contract offer was “fair.”

“We are currently analyzing this decision, but we are very disappointed with the court’s ruling which continues the stay that prevents our Administration from implementing common-sense changes in the AFSCME contract,” Rauner general counsel Dennis Murashko said in a statement. “These proposals include overtime eligibility after 40 hours instead of 37.5, the use of volunteers for state services, and a merit pay system. Every day of delay costs taxpayers over $2 million. Our contract framework is fair to the State’s taxpayers and employees alike and reflects proposals accepted by 20 other unions.”

While Rauner sought to implement contract terms after the declared impasse, a judge issued a stay that blocked those efforts.

The state’s labor relations board in November declared an impasse between the union and the Rauner administration. The union immediately vowed to appeal the ruling.

The union’s contract expired on July 1, 2015. In January 2016, Rauner asked the Illinois Labor Relations Board to step in and decide if negotiations with the union were at an impasse. The union has said the governor’s administration wasn’t bargaining in good faith by walking away from the table.

An administrative law judge in July ruled that the Rauner administration could impose some of its favored issues, but urged the two sides to keep talking. The judge heard more than a month of testimony.

Administration officials say AFSCME rejected proposals on overtime after 40 hours and on allowing volunteers to handle some of the worker’s duties.

The union says its members would have to pay 100 percent more in health care in the first year of the contract, and a 10 percent per year increase. There are also no pay increases over the four-year term of the contract.

But the administration official contended state workers were being covered by very expensive plans — with the vast majority of employees not opting to use the top coverage.