50 ILCS 135/12

(a) A member of any fire department or fire protection district may: (1) be a candidate for elective public office and serve in that public office if elected; (2) be appointed to any public office and serve in that public office if appointed; and (3) as long as the member is not in uniform and not on duty, solicit votes and campaign funds and challenge voters for the public office for which the member is a candidate. (b) A firefighter who is elected to the Illinois General Assembly shall, upon written application to the employer, be granted a leave of absence without compensation during his or her term of office.