(1) Aperson commits obstructing government operations if he intentionally obstructs, impairs, or hinders the performance of a governmental function by a public servant, by using or threatening to use violence, force, or physical interference or obstacle.
(2) It shall be an affirmative defense that:
(a) The obstruction, impairment, or hindrance was of unlawful action by a public servant; or
(b) The obstruction, impairment, or hindrance was of the making of an arrest; or
(c) The obstruction, impairment, or hindrance of a governmental function was by lawful activities in connection with a labor dispute with the government.
(3) Obstructing government operations is a class 3 misdemeanor.