SPRINGFIELD, Ill. (AP) – Illinois Gov. Bruce Rauner’s administration has filed an unfair labor practice charge against the state’s largest public-employee union, a move union leaders call an attempt to intimidate their members.

Rauner’s filing Thursday says it costs the state $2 million a day and is seeking damages. Union spokesman Anders Lindall calls the filing “frivolous.” The Republican governor and the American Federation of State, County and Municipal Employees state council are warring over whether the governor can impose the terms of the administration’s final contract offer.

Rauner ended talks last winter with AFSCME. A state labor board sided with Rauner last month saying talks were at an impasse. But a judge sided with the union and issued a temporary restraining order to keep the governor from imposing contract terms.