820 ILCS 130/11
No public works project shall be instituted unless the provisions of this Act have been complied with. The provisions of this Act shall not be applicable to Federal construction projects which require a prevailing wage determination by the United States Secretary of Labor. The Illinois Department of Labor represented by the Attorney General is empowered to sue for injunctive relief against the awarding of any contract or the continuation of work under any contract for public works at a time when the prevailing wage prerequisites have not been met. Any contract for public works awarded at a time when the prevailing wage prerequisites had not been met shall be void as against public policy and the contractor is prohibited from recovering any damages for the voiding of the contract or pursuant to the terms of the contract. The contractor is limited to a claim for amounts actually paid for labor and materials supplied to the public body. Where objections to a determination of the prevailing rate of wages or a court action relative thereto is pending, the public body shall not continue work on the project unless sufficient funds are available to pay increased wages if such are finally determined or unless the Department of Labor certifies such determination of the prevailing rate of wages as correct.
Any laborer, worker or mechanic employed by the contractor or by any sub-contractor under him who is paid for his services in a sum less than the prevailing rates for work done under such contract, shall have a right of action for whatever difference there may be between the amount so paid, and the rates provided by the contract together with costs and such reasonable attorney's fees as shall be allowed by the court. Such contractor or subcontractor shall also be liable to the Department of Labor for 20% of such underpayments and shall be additionally liable to the laborer, worker or mechanic for punitive damages in the amount of 2% of the amount of any such penalty to the State for underpayments for each month following the date of payment during which such underpayments remain unpaid. Where a second or subsequent action to recover underpayments is brought against a contractor or subcontractor and the contractor or subcontractor is found liable for underpayments to any laborer, worker, or mechanic, the contractor or subcontractor shall also be liable to the Department of Labor for 50% of the underpayments payable as a result of the second or subsequent action, and shall be additionally liable for 5% of the amount of any such penalty to the State for underpayments for each month following the date of payment during which the underpayments remain unpaid. The Department shall also have a right of action on behalf of any individual who has a right of action under this Section. An action brought to recover same shall be deemed to be a suit for wages, and any and all judgments entered therein shall have the same force and effect as other judgments for wages. The action shall be brought within 5 years from the date of the failure to pay the wages or compensation. At the request of any laborer, workman or mechanic employed by the contractor or by any subcontractor under him who is paid less than the prevailing wage rate required by this Act, the Department of Labor may take an assignment of such wage claim in trust for the assigning laborer, workman or mechanic and may bring any legal action necessary to collect such claim, and the contractor or subcontractor shall be required to pay the costs incurred in collecting such claim.
820 ILCS 130/11