820 ILCS 12/20: Authority to enact legislation affecting union security agreements.

(a) The authority to enact any legislation, law, ordinance, rule, regulation, or the like that by design or application prohibits, restricts, tends to restrict, or regulates in any manner the use of union security agreements between an employer and labor organization as authorized under 29 U.S.C. 164(b) vests exclusively with the General Assembly.

(b) No local government or political subdivision is permitted to enact or enforce any local law, ordinance, rule, regulation, or the like that by design or application prohibits, restricts, tends to restrict, or regulates the use of union security agreements between an employer and labor organization as authorized under 29 U.S.C. 158(a)(3).

(c) Nothing in this Act shall be construed as prohibiting the General Assembly from enacting legislation barring the execution or application of union security agreements as authorized under 29 U.S.C. 164(b).

(d) This Act is a denial and limitation of home rule powers and functions under subsection (h) of Section 6 of Article VII of the Illinois Constitution.