Mass. Gen. Laws ch. 149 § 27H
No agreement or contract providing for the cleaning and maintenance of public buildings or space rented by the commonwealth, shall be entered into or given by the commonwealth unless said contract or agreement contains a stipulation requiring prescribed rates of wages, as determined by the commissioners, to be paid to the employees of the maintenance or cleaning contractor. Any such contract which does not contain said stipulation shall be invalid, and no payment shall be made thereunder. Said rates of wages shall be requested of the commissioner, and shall be furnished by the commissioner in a schedule containing the classifications of jobs and rate of wages to be paid for each job. Said rates of wages shall include payments to health and welfare plans and pension plans, or, if no such plan is in effect between employers and employees, the amount of such payments shall be paid directly to said employees. Whoever pays less than said rates of wages, including payments to health and welfare funds and pension funds, or the equivalent in wages, on said works, and whoever accepts for his own use, or for the use of any other person as a rebate, gratuity or in any other guise, any part or portion of said wages, health and welfare funds or pension funds, shall have violated this section and shall be punished or shall be subject to a civil citation or order as provided in section 27C.
An employee claiming to be aggrieved by a violation of this section may, 90 days after the filing of a complaint with the attorney general, or sooner if the attorney general assents in writing, and within 3 years after the violation, institute and prosecute in his own name and on his own behalf, or for himself and for others similarly situated, a civil action for injunctive relief, for any damages incurred, and for any lost wages and other benefits. An employee so aggrieved who prevails in such an action shall be awarded treble damages, as liquidated damages, for any lost wages and other benefits and shall also be awarded the costs of the litigation and reasonable attorneys fees.
Mass. Gen. Laws ch. 149, § 27H