Section 27 of The Swedish Co-Determination ActVersion 2021:1114, English Translation

KollektivavtalCollective Bargaining Agreements
27 §Section 27

Arbetsgivare och arbetstagare som är bundna av kollektivavtal kan ej med giltig verkan träffa överenskommelse som strider mot avtalet.

Employers and employees who are bound by a collective bargaining agreement may not enter into any contract that does not comply with such collective bargaining agreement.